The guy is a great draughtsman and all, but I notice that he does some extremely photorealistic paintings of celebrities that seem relatively devoid of any interesting interpretation of their subject. I don't know why he bothers with them when he can do "the other" so well. I also notice that the paintings you posted seem completely atypical of his work. What got you interested in him?
I have a big oversized book of his caricatures. A former co-worker posted a link to a demo he did and that started me on a surfing binge. I think the photo real stuff is just part of the process of mastery of every feature. Leading to the caricature. Here's that demo.http://www.youtube.com/watch?v=b18LOHBjyuc