Le Fish Swag - Healthy looking or NO?!

Wondering if the office fish, named Swag, looks healthy or not!? The girl who bought him left for Ecuador and I am in charge of him now...I know nothing of fish. This has been a great and informative site. Does he look healthy?

ALSO-- I added those little jewels to his tank and he seems to see his reflection more and get angry at it. Is that bad? Also also--he loves the warmer water I changed for him!! I am going to buy a little heater for him hopefully. I have no idea how big the tank is, though.

Brittany