This might sound strange but to me Hamels' mugshot on mlb.com doesn't look like him or, at least, it doesn't resemble what Hamels' looks like in my minds eye.
Given no prior knowledge of Hamels I reckon most people would say this was two different guys...
Facegens can only really be done from profile pictures, therefore it's very difficult to capture Hamels with facegen. Doesn't help that he always goes clean shaven for the mugshot and then has a beard for most of the season either.