He looks like a normal young Belgian to me. Actually he has more weight than many young Belgians.
I don't get many such comments about the Black Dogs because they are so hairy, it's hard to tell what their weight is. But one of my friends has a young male Black Dog and several people at the training club almost convinced her there
had to be something very wrong with him because he was so skinny. They'd touch him and get all alarmed "OMG! He's so skinny! What do you feed him? How much do you feed him? Have you taken him to the vet?". He's her first Belgian too, which sort of makes it worse.
It's funny though, how different people have different perceptions about that stuff. Another friend has a young, skinny little Mal girl and at a big show a few months ago an old dog guy commented "now THAT is working size and weight!" while we were ring side. I'd say at an AKC show, you could get all sorts of comments from all sorts of people about if your dog is too skinny, fine, just right, too fat, needs more exercise, needs less exercise and more food, etc. Different breeds all have their norms and someone with show Labs would very likely find most Belgians to be too skinny. Other Belgian people, probably not so much although some will obsess over trying to get and keep weight on their dogs (probably because someone else made them feel weird about their dog's weight at some point). Just be glad you don't have a one of the super skinny sighthounds breeds or you'd probably hear that sort of thing every time you had your dog out anywhere
ETA: Just showed the picture to my husband and said someone commented that this dog was too skinny and needed to be fed more. His reply "Oh brother - that's a good looking dog there!".
