This quotation is from a 2014 Cosmopolitan blog post. The author of the answer is a young man; presumably the author of the question and most of the readers are women:
Q: I usually wear heels because I think they're sexier, but lately I've been going for casual drinks in flats and getting hit on. Is there something to a flat shoe that's enticing, and which ones should I be wearing?
A: It's possible that guys see your flats and think, "Hey, she seems chill and low maintenance." Or that they are less intimidated than they might be if you had the added height a pair of heels would normally give you. It's also possible that they never noticed your shoes in the first place and were responding to something you were not even aware of. There's really no way of knowing.