It kinda looks photoshopped to me... look at the way the horse is standing. If he did have that weight pulling down on his neck, he'd have to put his front legs forward more and brace his neck. It doesn't really look like he's doing that so I'd have to suspect its photoshopped.
When I bestride him, I soar, I am a hawk: he trots the air; the earth sings when he touches it; the basest horn of his hoof is more musical than the pipe of Hermes. ~William Shakespeare