I think you did well in getting the details of the clothing down, even with a rather small reference to work from. I like that you thought ahead to say 'if he were an animal, how would it work on his tail, legs..." and added the bandages and the buckles on his lower legs there. The details and coloring here is superb, great job in doing the black besides and coloring in that cool cell shading is nicely done.
His right arm, the one that is up, however, isn't quite high enough, even though I know it's bent behind him some, the elbow seems a little.. short. It could be the perspective is just throwing me off, but it does just look a bit low. Though I'm not a big fan of cutting out one toe on anthro's, I know it's a style, it jsut looks a little strange to me, but the legs and paws are great, even down to the fold of skin an d all. His other shoulder, facing us, his left, also seems maybe dropped a little too low- not by much, but almost in a disconnected sense- but, like I said, not too much.
It does very much feel like a poster and that's awesome, I like the feel with the name on the side, the border and even the spray painted 'bad' on the backdrop. Definitely gives it more dimension by putting a bg on it, even if a basic one, I like it better than if it was just plain white. Adds more to the whole effect.