"Justified true belief isn't enough to account for knowledge, woooooo!"
Didn't get the joke?
The hover over text is a reference to the Gettier Problem.
The comic is a reference to the fact that life is pointless. (Actually the last quote is from the main character in Nausea, and really shouldn't be attributed to Sartre properly, as it often is, because he wasn't expressing his actual opinions there).