Is the meme in question a real life one (and if sho, which one)? Or is it something within the setting of Luke and Cory and Nat and Dm, etc, and we'll be hearing more about it as we read on? or is it an oblique reference to another tabletop comic, because if so which one?

Is that black box supposed to be Gordon, or is there someone else here?

If you mean the beige background, that's always been Gordon's speech.

Oh, you mean the one with a white background; seems like an obvious coloring error.