Other mistake: When Rocky is in the funhouse looking at himself, he appears to look relatively "normal". But it's very obvious that it's got nothing to do with the mirror, and more to do with the removal of a lot of makeup. For example, Rocky usually has almost no nose, but in the mirror he has Eric Stoltz's very well developed nose.
Mask (1985)
1 other mistake - chronological order
Directed by: Peter Bogdanovich
Starring: Laura Dern, Sam Elliott, Eric Stoltz, Cher, Estelle Getty
Deliberate mistake: The mirror that made Rocky's face look normal should've made his mom's face look different, but her face stayed the same.
Rocky Dennis: What's his problem, Ma?
Rusty Dennis: Nothing. He's just another asshole. You let that negative dreck in and it'll put ya away. You can be a chickenshit and die or be a mensch and keep makin' yourself well.
Trivia: During the baseball game at the camp for the blind, notice the extra actor standing to the right of second base. She reaches back and pulls her underwear out of the crack of her bottom, apparently oblivious to the camera behind her.
Question: When Rocky kisses Dianne, why is it a New Years dance if they are at summer camp?
Answer: It appears to be a party at camp. Lots of camps have special themed parties especially before the camp is over.