Hollywood loves to be meta, and there's a long and glorious history of films referencing film-making, and indeed other films, or actors breaking the fourth wall to confirm some self-awareness. But what Hollywood loves more, is being remarkably clever with those references, from George Lazenby quipping "this never happened to the other fella!" in On Her Majesty's Secret Service, to Scream and Wes Craven's New Nightmare referencing their own film-making and genre conventions, and John Travolta remarking on Hollywood's tendency to make "unbelievable, unremarkable sh*t" in Swordfish just a year after releasing Battlefield Earth.
But it isn't all just whiteboards featuring famous horror monsters (Cabin In The Woods) or Ghostbuster cameos in Casper, or even Julia Roberts playing a character pretending to be Julia Roberts (Ocean's 12), because there's another level to that often smug and self-satisfied clever-dickery. We refer, of course to those moments when actors portraying other characters make reference to films they have also starred in, in a complicated loop.
These are the more complicated, and more rewarding meta-references to notice, and there are more of them than you might actually think, and of course it's all terribly self-congratulatory on Hollywood's part.