A term invented by some dumbass who found the proper way to describe the people well-known throughout Tumblr was to group them together by a definition that does not even exist.
The dumbass who invented this term was most likely someone who bitches about not having enough followers, and to make him/her-self feel better about their lack of acknowledgment, labels everyone who falls under his/her description of "Tumblr famous" as an attention-seeking whore who has gained their fame through their looks.
That idiot, most likely drew this assumption without reading their posts and making an attempt to discover why they have such a large amount of followers.
I honestly don’t know why most of the Tumblr famous people are famous at all. They post stupid shit and add “like a boss” to the end of everything and still get hella notes. I hate how someone not Tumblr famous can post something that actually makes sense and get half the amount of notes. Looks are all some people care about on this site.