Basically what she’s doing is trying to figure out if she has a shot with you. She knows what she’s bringing to the table. She’s just trying to figure out if you like what she brought.
Also, if a girl with big boobies with no tushie asks you this question, say boobs.
It’s basically a casual way of being like “Am I your type?” and then you can be like “Yes. Yes you are. Let’s intercourse each other.”