They replicate a dot matrix printer which prints the message.

Like that Chemical Brothers music video. Hey boy, hey girl or whatever it was called.

They made a pc build video which was bad. Lots of bad stuff in it which you shouldn’t do when building a pc, sort of stuff which would make common sense not to do. It got ripped to shreds by other YouTubers who did their own videos about it.

Probably still all on YouTube.