First, a video:
This is a closeup of my TV, of a still picture (the Xbox One menu)
There is no motion, the TV has all filtering, sharpening, etc disabled.
Could it be that the TV can't make the color range needed so it toggles pixels to approximate it? I remember software on the Atari ST and Amiga toggling between to images to approximate extra colors.
The TV is a LCD TV and the connection is through HDMI.