The horse is absolutely beautiful, no question. I saw him on Monday. I think his legs look normal for a recently retired racehorse who isn't even 3 full years old.
It IS a bit weird how, in the ad, he appears to be hovering over the safe pavers. I think the photo was probably taken right where he appears to be standing/hovering, so I don't know what's going on with that.
Here is my own photo. He is not stood up perfectly, but he looks mostly the same as in the ad.