An original chick flick is a movie that really is stereotypical to the sub-genre called "chick flicks." A movie that is so much a chick flick that it ceases to be just a chick flick and instead becomes a new and improved type of chick flick: "Original Chick Flick."
A: So what kinds of movies do you like?
B: I like pretty much everything. I do have to admit, though, that I have a special soft spot for chick flicks. Like, "Definitely Maybe," have you seen that one?
A: Man, that's not a chick flick. It's an Original Chick Flick.