Sorry about that one. This was accidentally caused by what we believed was a minor backend update (which we have since rolled back).
Fun Fact: This is what we use throughout all our internal testings for new content whilst it's still being developed. We only really replace this with 'Final Level Art' as we get much much closer to shipping it. It's strange seeing it out in the open!
This will slowly disappear over the course of the evening as the servers change back.