It's a way to pick up girls. How it works is you use remarks to
tap into female insecurity; Shake their confidence.
Neg is a negative remark wrapped in a back-handed compliment.
So your
neg will confuse and intrigue them and maybe even shake their confidence a little bit, but only enough for them to fall from the clouds and be interested in talking to you. Its way to get threw their defenses at bars and such.