I guess the joke is that there is a Justin Bieber song called "Sorry". At least I think what's going on here. "404s and Heartbreak" with a pic of Kanye West would have been something else along this line.
Yeah I don't get it. I guess the only other thing that stood out for me was that the message is "Sorry something went wrong" except that 404 is a user error. "Sorry" is usually used for 500s.