Breaking the fourth wall in film is both a radical concept and one that’s readily familiar to audiences, even if they don’t know the phrase “breaking the fourth wall.” Acknowledging the audience in some form or fashion has happened in everything from Disney animation (as when Scar objects passionately to hearing the song “It’s a Small World” at one point in “The Lion King”) to ’80s-era teen comedies to the Marvel Cinematic Universe. But every so often, audiences are thrown for a true loop when the fourth wall, that demarcation point between the big screen and those watching what’s displayed there, is demolished so swiftly and inexplicably that there’s nothing left but the rubble. 20 years ago, one such moment happened in a mainstream, big-budget sequel that was established to take place in some facsimile of the real world without automatically occupying space in our real world. The film is 2004’s excellent “Ocean’s Twelve,” and the scene in question occurs when Danny Ocean’s wife Tess is called upon to play a critical role: Julia Roberts. Seeing as Tess is played by … Julia Roberts already, that complicates the matter just a wee bit.

It’s not as if the 2001 remake of “Ocean’s Eleven” didn’t establish itself as a film that exists in something awfully close to the real world. It’s not just that the original film is set and shot in Las Vegas, down to the masterful final scene with most of the eponymous crew standing in front of the famed fountains at the Bellagio. The key event during which Danny Ocean (George Clooney) and his fellow thieves steal hundreds of millions of dollars from a vault combining money from a few different Vegas casinos is also a prize fight between real-life boxers Lennox Lewis and Wladimir Klitschko. (Add to that the fact that when Ocean is first freed from prison, he makes a call to his parole officer directly in front of a Trump Tower, and real-world connections are impossible to avoid.) But while it’s easy to look at the first “Ocean’s” as a subtle commentary on the power of film stardom, and treating tough-guy characters like the shark-like businessman Terry Benedict (Andy Garcia) as stand-ins for film-studio executives, the 2004 sequel ramps that connection up to impossibly high levels. Benedict returns in that film to exact revenge for the money he lost at the hands of Ocean and his crew, but his demands for the dozen boil down to: steal back what you already stole, and then steal some more. It’s a version of how filmmakers are told that a sequel has to be the same as the original, but with more, ostensibly to please the same audiences who flocked to the first one.

Ocean’s Twelve’s most meta moment has Julia Roberts playing ‘herself’

The meta aspects of “Ocean’s Twelve” get almost overwhelming when Tess is roped into the situation. By the time the remaining few members of Danny’s team call her, they’re in Italy, she’s in the American Northeast, and everyone else is in jail after having been caught attempting to steal a priceless Faberge egg. The basic plan is for Tess to play a “small role” in the heist by pretending to be Julia Roberts so that she can see the egg in question and the theft can go off without another snag. But just as the very fact that one of America’s most famous leading ladies is being called upon to play a character who has to play her serves as a comedic snag, the problems get worse when none other than Bruce Willis, playing himself, shows up and acts friendly to Tess (because he doesn’t realize she’s not really you-know-who), accompanying her to the museum. That this gambit doesn’t work as planned (at least initially) should come as no surprise, but the gambit itself takes a supporting role to all of the references to real life throughout this sequence. No doubt that comedy is subjective, and if you don’t laugh, nothing can convince you, but this is arguably the funniest scene in Steven Soderbergh’s filmography, and among the best of Roberts’ own career for how willing she is to mock herself.

Once it becomes clear to us that Tess is being called upon to play the actor who plays her to begin with (first thanks to some subtitled dialogue between a hotelier and his fellow staff member), the script begins leaning into in-jokes about the actor’s life and career. Just as Roberts herself isn’t in as much of “Ocean’s Twelve” because she was pregnant at the time of filming, the remaining members of Danny’s crew, including Basher Tarr (Don Cheadle) and Linus Caldwell (Matt Damon), start trying to coach her on how to be Julia, including how to “protect your fake baby.” Of course, part of the humor is that they get some of the details wrong; when Tess-as-Julia has to hiss at them that the actor didn’t appear in “Four Weddings and a Funeral,” it’s a good gag for two reasons: first, for the pop culture confusion, and second, because Roberts did appear in “Notting Hill” with “Four Weddings” star Hugh Grant. And the back-and-forth she has with Linus and Basher as they try to get her in the right headspace feeds into popular beliefs about famous people. When they tell her that “You’re playing an actress, they’re insecure,” and she snaps back, “I’m freaking out!,” they cheer her on, even though she’s not doing it to embody her part.

This Ocean’s Twelve moment is as inside-baseball as it gets

When Willis shows up, thanks to coincidentally staying at the same Italian hotel where Tess and the others are, the meta humor becomes almost delightfully alienating. It’s not just that Willis’ cameo is punctuated by a running gag in which multiple people tell him politely but smugly that they “knew” about the big twist at the end of “The Sixth Sense” without even naming the film. (Or that Willis, at one point, mutters to Tess-as-Julia that if so many people knew the twist, “If everyone’s so freaking smart, how come the movie did $675 million worldwide?”) Willis is there as a friend of the famous actor, even as he has to accept an unplanned jibe from Linus, who tries to distract Willis by noting how much he must understand “that little statue on the mantle smirking” at a fellow A-Lister. The end of this meta rabbit hole is both simple and ridiculous, as Willis attempts to call Roberts’ home to see if he can get one of his kids’ toys back; when Tess takes the phone from him to conduct the call and maintain the charade, she winds up on the phone with … Julia Roberts.

To enjoy any movie, you have to suspend your disbelief. To enjoy the “Ocean’s” trilogy directed by Soderbergh, as is the case with any solid heist picture, you really have to suspend your disbelief, because otherwise, you could nitpick all sorts of issues. But disbelief can’t even exist if you want to enjoy a scene in which Julia Roberts has to sit in almost stoic silence as men natter on about her accent, her voice, the way she looks, etc., all under the guise of not actually being the actor but being someone who just looks a lot like her. There is no world in which you can think about the questions raised by the moment in which Tess is on the phone with the actor who plays Tess (and only one of the two of these “characters” is aware of what’s really going on), without making your head spin or your nose bleed. The joy of this scene is also what makes it so divisive and controversial; it’s so inside-baseball, so navel-gaze-y, so self-referential that it starts to feel like a scene that exists purely to entertain the people who made the movie.

Bruce Willis knew exactly how to play this scene from Ocean’s Twelve

It’s not that “Ocean’s Twelve” is not playing on gags about its stars, who had become even more famous in the period between 2001’s “Ocean’s Eleven” and the 2004 sequel. Clooney gets to do a running gag with some of his co-stars in which he asks them how old they think he is, and he’s almost horrified at the answers. Damon, who was juggling filming this and the second Jason Bourne movie, gets to play an inverse of that cool and collected amnesiac spy, as he fumbles his way through a coded conversation with Danny and a mysterious and enigmatic Eastern European. But there really isn’t quite anything that tops the extended farcical comic setpiece that winds up with everyone going to prison. Part of the sequence is nothing less than a happy accident, since Willis was purportedly in the mix to play Benedict in “Ocean’s Eleven” before Garcia stepped in. Would this scene work half as well without Willis’s blend of insouciance and annoyance at “Julia’s” handlers and her loopy doctor (really just Carl Reiner’s character Saul in disguise)? Though there are other actors with whom Roberts had worked prior to this film, from the aforementioned Grant to Denzel Washington, Willis just seems like the only A-Lister who could show up in such a knowing sequence playing himself and having fun with it.

That latter part is key: having fun. It’s a fair claim to note that the “Ocean’s” trilogy works as well as it does, or at least moves as smoothly as it does, because it looks like everyone involved in the film had a great time. For “Ocean’s Twelve,” a film that has key scenes in Lake Como, where Clooney had a villa, the notion that everyone on screen had a great time almost became an easy critique. There’s a reason why some outlets have dubbed this one of the worst sequels ever (even if it’s not), and much of the 2007 capper “Ocean’s Thirteen” feels like a corrective for the less widely beloved “Ocean’s Twelve” down to Clooney facing off against an actor from the “Godfather” franchise in the form of Al Pacino. 20 years later, some people may remember the extended riff on “Entrapment” in which the sly thief played by Vincent Cassel all but dances his way through a powerful field of lasers to steal that Faberge egg, but the scene in which Julia Roberts is playing herself and someone else who has to pretend to be her may be the apotheosis of people’s frustrations.

Again: humor is subjective. Either you find it funny or you don’t. But this style of humor is best summed up in the way the Academy Award-winning actor is credited in both the first and second films. In “Ocean’s Eleven,” the title card reads “And Introducing Julia Roberts as Tess.” In the sequel, the title card reads “And Introducing Tess as Julia Roberts.” If you’re on the right wavelength, this is the tip of the enormously funny iceberg. For everyone else, though, it may just be too odd. Their loss.