My wife and I were visiting my parents for the holidays in 2001 and my wife decides we should take my mom to a movie. So they picked Vanilla Sky and none of the three of us actually knew anything about the movie. So when that line was said by Diaz, and I'm sitting next to my mom, I literally choked on popcorn to the point I had to leave the theatre and compose myself outside. Then I went back in the theatre and my mom and wife were laughing at me and I just told them not to talk to me for a couple hours.
Yes, I think that is exactly what is mean by an unexpected line.