A back-handed compliment; a snide remark; a sarcastic comment; a compliment followed by an an insult; when someone searches for something really nice to say, but can't think of anything so she compliments you on something very obvious.
Girl 1: Wow, did you do something different?
Girl 2: Yes, I cut and bleached my hair blonde today!
Girl 1: Oh, wow, it's so... blonde and...wow, what a cut...
Girl 2: Uh, thanks? But that was like a compact diss.
Girl 1: Sorry...