More people are starting to understand that this is a stock expression that is unfortunately way over-used in mainstream animation, and that it's not just Dreamworks studios that does these sassy looking faces for marketing purposes. (I am exempting Buzz from this since he is supposed to be a consumer product in the movie.) I am also getting pretty tired of listening to people who can't really tell the difference between these two studios other than from this PIXAR VS DREAMWORKS meme image.
Anyways, as John K. would dub them, they are your smartass 'Tude expressions. The kind of lazy stock expression that doesn't need any sort of characterization, and can consequently be slapped onto any ol' character's face. I'm glad he specifically made sure to not make this face in any of his Ren and Stimpy in-betweens, hahahaha.