When CG animation came out, it looked so different and so fresh compared to 2d animation that we could get away with a lot but the novelty effect has faded and the bar has been raised very high with CG entertainment. Funny enough, technology is finally enabling us to … go back to the appeal of the 2d aesthetics!
Shaping the mouth corners is one of those 2d tips used in top studios to make the characters look less CG. By moving the outside corner closer inside the silhouette of the character, you will make the mouth shape more stylised and closer to what an illustrator would craft rather than a stupid computer.
Doesn’t the tweaked mouth shape look clearer and more appealing on this Sony’s “Angry Birds movie” presentation? I am posting the picture twice just so you can flip it and the link to the video is below.