I took a couple of screenshots from an internet video to illustrate what I'm seeing. The quality of the video isn't the greatest to start with, but you should still be able to see what I'm talking about.

The first image is "normal" quality.


The second image, a frame or two later, shows the glitch that I'm talking about:


It seems to repeat every second, on the second.

Is this normal? Or, should I report this as a bug?