RORY: Francie, so good of you to stop by. I know how busy you are. Gum? [hands her a piece]
FRANCIE: What’s your damage, Gilmore?
A reference to the movie Heathers, previously discussed. In the film, “What is your damage?” was a way to sarcastically ask what sort of mood someone was in. It’s from the 18th century slang “What’s the damage?”, meaning how much does something cost.
There have been several references made to this film in Gilmore Girls to highlight a “mean girl” plot line.