I think that is a beautiful horse. I don't know the standard for that breed but I can see what the other person said about the hind quarters. Maybe a bit thin through the loins or thin about the barrel? Either way it seems minor to me. Nice top line. And what a gorgeous mane!
One more idea is that it might be better to look at the offspring and not the parents. My Baby horse did not look anything like his father who was a big fancy Arabian. A pretty horse does not means that the genes will be expressed in the foal.