Maybe don't keep the mirror in his tank; it can exhaust him if he thinks the "other fish" is a threat and is always in his home. I have a mirror that I put beside their tank for about 3 minutes a day just to give them some exercise.
Also, feeding time can be a lot of fun. Junior loves bloodworms so I'll dangle one just above the water for him to jump for, and then I'll move it so he has to chase it. Live food, such as brine shrimp, may be fun for your fish to chase, too, if you're interested in that. Just be sure to rinse it off first.
I also talk to my boys. They are very curious fish so mine will swim up to the surface and look up at me talking to them.