Video: When movies break the fourth wall it's always a little jarring. Like when you see someone you don't know try to talk to you and you look behind your shoulder to see if it's really you they want. But when characters express that awareness of being in their world to you, it can get pretty fun! For comedic purposes and dramatic purposes, it's an interesting tool that filmmakers use.
Here's Now You See It explaining how to break the fourth wall in movies.