The cat looks content to be sleeping, and I think the pose is great. There seems to be some light leakage though, or something also that has made the bottom of the image foggy. Did you manage any that are clean? you must have been pretty close if all you were using was a 50mm lens and a teleconverter!!
I took the photo through glass at the zoo the foggy patch at the bottom is probably reflection all my shots were like this but i think it gives the image a dreamy like feel.