Looks like Gnome have made their own attempt at a cutesy "oops" message, as seems to be the trend now.
While messing around with Gnome's css style and using Alt-F2 and r to reset the decoration, "something went wrong" and I got a computer with a sad face on it saying "Oh no!".
I don't find it that annoying, though. It's endearing as kind of failed attempt at being hip like a Google product or something. Gnome's just not quite there yet.
Funny that I got this the day after reading this hilarious post.