Which horse did you want critiqued? You have 3 different horses pictured.
I'm not very good at critiquing but you should try to get pictures of the horse alone. Get standing as squared as possible, on a flat surface. Try to get one of his complete body on both sides, his front, and his back end. Try to get all of him in the picture (hooves included) and not just his head (which is adorable by the way).