It looks like what's called a dangerous pose in the portrait business. As far as the vertical composition versus a horizontal, in the shot as-shown, the baby occupies less than 10 percent of the frame area. To me, that makes for a boring photo, since the prime real estate happens to be the cloned-in wall area at the upper levels of the image. I wonder what it would have looked like with a closer-up framing of the child, and less wall above her. This shot is a novelty pose,and I think a larger image of the baby would make it stronger.
I think the idea is novel, but it does look a bit unsafe for a newborn, with the hardwood floor and the rocking horse's rockers and all that. I was thinking though, as I looked at the shot, what a dedicated people photographer you must be, to have a wall in your home that was painted so as to be a nice brown toned background....and then you told us it as cloned in texture...a crushing blow...