I came across an interesting interview with Platon on the the radio the other day. He is a truly gifted portrait photographer who works for the New Yorker and Time magazine amongst other publications. His images are a clean form of portraiture where often there is no environment and he works in monotone. With his work you get a deeply focussed image on the person that works in conjunction with the editorial article that usually accompanies it. When he does include other elements they add to the power of his images.
Listening to the interview reveals the classical approach in that a good portrait photographer has to have an insight into the subject that he is shooting. From this understanding I believe there is the foundation that good portraiture can give us a great insight into the subject – an insight that is much more than the image alone.