Same! I distinctly remember seeing portions of this wallpaper that led me to believe it's procedurally generated and not simply a collection of video files, and had to rewatch it to confirm. There are several points where the date and time match the system date and time down to the second.
I'm being pedantic but I liked your comment. Most TVs today are giant ARM computers, ~95% of TVs ship with ARM Cortex but only about 35% have some variant of Android.
Most LED backlights are wired in such a way that when one LED fails it bricks a significant portion of the panel backlight. You'll knock out entire rows or huge portions of neighbor backlight LEDs when one fails. Basically it's a cheap way to ensure a whole row of LEDs are the same brightness but the tradeoff is one LED fails and it looks like 5% of your screen went dark.
It seems like a good beginner-intermediate thing that'd be approachable to learn with a basic multimeter and beginner level soldering skills.