Its very clearly one Panda Cory following its reflection. Lots of fish do this. I've seen cories do it a million times. Not unusual at all. As long as your tank water parameters are normal, well filtered and oxygenated, then there is nothing wrong with this fish. Each individual is a little different. Some do this more than others but eventually most give up on it and chill out. My Pictus cats were doing it the other night. Also, if this Cory is new to the tank then I'd say its very normal. New fish seem to do this more as they get acclimated to their new homes.
Btw... if that were two fish then they'd have uncanny timing following each other perfectly. One fish, following its reflection. I wouldn't worry.