Allot of good comments here...
I viewed many of the actual owner's videos. Link below:
http://www.youtube.com/user/nancyj0/videos
According to her, the fish is breathing heavily because it just ate a whole sheet of nori, and was pacing the tank excited about the possibility of more food, and it sometimes does that while playing with (or possibly fighting) it's own reflection in the glass...
I agree that this fish is too big for the tank, but have to give the owner some credit. As the fish grew, she did her part in providing larger and larger aquariums to accommodate the larger fish. I believe this is her 4th or 5th aquarium for this fish in the 5 years she has owned it. It actually started out in a 24g tank as a baby. Many of us plan upgrades, but rarely actually do it...
That being said, this fish is probably still too large for this tank, and it may be time to donate this fish to the nearest public aquarium.