As others have mentioned, it's when a theater or television character acknowledges the viewing audience, and turns to talk directly to them. I can't see why this has anything to do with what the OP was suggesting, however.
It would break the fourth wall because they would know that they are living in a theme park. They would know that they are performers and talk to people outside that park. I have not seen other Disney characters do that formally unless if its a game app or for a movie promotion.