It has been touched upon many times before, but her assistants do all the work from what some assistants who I have met have told me. I saw the actual prints from this book in person and even my girlfriend was picking them apart, which is pretty bad since she doesn't know much about photography. I don't think she does much original work and if you replaced the celebrities in her images with normal people who would care? Compare her images to Avedon's western portraits.
She just seems hollow and a fake to me. Amoungst my friends she is referred to as Lieboshitz. But what the hell do I know. I can't take a picture either.