That video thumbnail reminds me, there was a shirt RT/AH was selling that looked like that. It was "RYAN THE [FILL IN THE BLANK] GUY", because it was a common bit in the videos to call him "Ryan the *whatever* guy". At an RTX, all the AH guys wore these shirts and filled in the space with whatever. Gavin decided to make his shirt say "RYAN THE BABY ANUS GUY"
Edit: I should note that I'm not saying this as a "HOLY FUCK GAVIN NEW!!! I'M A HUGE FAGGOT". i just thought it was funny given the context. I think it was a joke from a video.