This is a very cute pose, but I'm not sure it's filling the frame. More than that, almost everything - the line of the boy's face, the horse's eye - seems to be somewhat out of focus. I'm not sure what (the ear? the fence?) the camera latched on to, but the depth of focus wasn't enough for it to bring all of the two main subjects into focus. The background being blurred out is a nice effect, but would be stronger if the subjects were in focus.
wonderful moment. caught relatively well. did you crop this small section out of a larger one? the quality seems a bit lost. The expression on the boy is priceless.