This photo looks way too saturated as the hands have a lot of noise on the. The size is ok, but you will generally do a lot better if you use the full 640 measurements.
First, I recommend that you try a larger image next time. The crop is a bit too tight. It's a good idea, I mean poker is definitely "normal activity" (quoted from the challenge guidelines), but I think it could've been presented differently. As it is this is a very average shot.