The things that strike me for improvement centre mainly on the face and hair. The face is always going to be a focal point, it just looks a bit flat, try and push the smoothness and highlights/contrast there. The reds couuuld be a bit smoother maybe, I suspect the pictures are just making that look a bit blocky though, as Einion said, these are very unmerciful closeups. The white parts, however are awesome. You can see the really smooth transitions in shading there, as you can with the writing and accuracy with it. I'd reckon on getting better pictures. There are elements of it that I honestly suspect aren't done justice with them.