What's that mysterious moving light?

So, the other day I was sitting on the couch checking my email and I noticed that Bailey was kind of going crazy about something.  I looked over and saw he was intently staring at the wall but I couldn't tell what had his attention.  I went back to typing and saw him going crazy again.  This time I realized that the sun was reflecting off of my watch onto the wall and when I typed it moved pretty quickly and drove him nuts.  I decided to play with him a bit and took a video of it.  Enjoy!