Depends on how it was said and the tone...
Could be either or both, depending on the context.
It depends in what context it is said.
I say a compliment, but I am a glass half full kinda girl.
It's an ambivalent comment....
Depends on their face ex<x>pression
It could be either depending on the delivery. At a guess the person who said it likes you and isn't able to quite put into words why. It seems a strange thing to say unless you specifically asked that question.