That's amazing :3
I absolutely love it, it's swimming right?
The biggest "flaws" with it are actually really simple fixes.
The mane on the back should probably be just a little bit taller, and the back front-facing leg is just a tad off. I did a quick sketch (not a redline, bc I didn't know if you would be cool with that. I think I managed to get it in the same angle tho

Anyway, the only problem with the leg is the missing knee joint.
There are other ways you could position the leg too, just with it higher up on the body the knee joint would be visible instead of stretched out, if that makes sense?
That being said, I absolutely LOVE the little picture, I love the way you did the tail and the ears. So adorable <3