Man that looks weird.. my impression is that it looks like you used some sort of stylistic filter to make it look like that. Some sort of pixelisation effect. I know it's really exists like that, but the effect, to me, is of cartoonish clip art pasted onto a picture. I think it's the head on angle, not only does it make the facial expression look even goofier than I remember it, but it hides the true shape and structure and gives it a two dimensional look.
I really hadn't realized the 2D look until you mentioned it, but since you have, it does kind of look that way.
