Needs more shading at the edges, and more like, highlight. But obviously very diffused highlight, so's not to make it look non-matter. Basically it needs a bit more structure and contrast
yeah also the SL UV for the lips needs tweaking on the bottom.. i ran across that difficulty 1st when I tried to follow the lines hehe.. it dips in where you wouldnt expect it to based on the UV, right?
one thing I did do.. was use the pen tool to create my lip outline as a shape.. since its easy to pull in or push out without dealing with erasing, unerasing/drawing in pixels etc. Pen tool 4 lief!