Your picture is very arty, light from the outside is a very nice "source". If you can put a piece of white poster board or white foam core on the other side of the cat, it adds "fill" light, and just allows for a little more detail on the cat's right side.

I love the picture the way it is, I just think it would also be cool to see another picture where a wee more detail on the other side of the cat's face could be seen.