Art is a science, and most of it involves understanding the form of something in space. <a href="http://3.bp.blogspot.com/_qjUt6oT1j3c/S8dXF1fWUfI/AAAAAAAAAE">http://3.bp.blogspot.com/_qjUt6oT1j3c/S8dXF1fWUfI/AAAAAAAAAE</a> w/oaIftOmMVYY/s1600/andrewwyerth.jpg That looks real because all of the value, all of the colors involved are almost perfectly in the places that they would actually be if she was real.