What is this circle on video playback?

Hi all,

I just updated to KODI 17.0 on my NVIDIA Shield the other day and I love the new interface and features. One question, though: I keep seeing this weird circle on the right side of the TV during video playback. It also shows up when I am looking through video files on my external hard drive. Anyone know what this is and how to get rid of it? It shows different things at different times. I have seen people’s faces in it at times and what look like animated faces. I thought it was a screenshot from a webcam at firt, but I don’t have a webcam attached to my TV.