Looks very realistic and nicely done! Props to you!

First of all, the shading technique here is excellent, keep it up. All the shadows and highlights and values are great. And for the most part, the proportions are accurate.
BUT the proportions that aren't accurate do stick out to me. Not that there are many in this picture but to me it seems the right (anatomical right) arm is a noticeably short and the facial structure is quite off and a little flat.
I will say though, the hand on the right arm does look fantastic.
Good job!