solution...
The word "Youtube" is in quotes, which means it's referring to the word "Youtube" and not the brand or the service itself.
CRT can mean "Critical RaceTheory" or it can mean "Cathode Ray Tube". In this case it means the latter, even though there is a pic of some Critical Race Theory stuff in the toot.
The word "tube" was slang for an old-style television, because TVs worked by using a cathode ray tube, which was a special type of vacuum tube. (The word "tube" was used for vacuum tubes because of their usual shape -- a glass tube, even though a cathode ray tube is not shaped like that.)
When Youtube was started, it used the slang word for a TV, "tube". So the brand name "Youtube" is derived from "cathode ray tube", which is abbreviated as CRT.