Love how the fish-eye lens works in this composition. It really makes the horse visually pop out the viewer. Colors are vivid and details are nice and sharp. Shot is taken at a slight angle too which gives the gives the appearance of the main subject appearing on the diagonal. Not sure if that is a good or bad thing but it does add some visual interest. Now onto areas where I think that this image needs some improvement. First, expressions can really give a composition that added 'omph' to make it more eye-catching. I see a bit of the horse's eye and his/her expression a bit but not the rider. For the image to be more visually appealing AND play into the title you need to show us the girl's face. Show us her joy and delight at riding the horse. Help us make a connection. Not doing so I feel is the major weakness of the composition. Had you captured a joyful expression by showing the little girl's face it would have moved the score from a just above average shot into the stellar category. A minor flaw is that there is an odd shadow that appears over the chest of the horse. Personally, I would have loved to have seen more of this horse's beautiful coloration.
Might have been even stronger if you had been the other side of the horse so we had eye contact with both the horse and the girl, instead of them both looking away from the viewer ?
Otherwise very nice. Good PoV and use of wide angle.
While I appreciate that you were trying to give us a unique perspective, I'm just not sure the fish eye look does well here. I would really like to be able to see the riders face, and a bit more of the horse face too.