It was a video of putting a 3D print in a microwave with a large container of acetone, another container of primer, and hitting the popcorn button. The real life result would be a fire, not a perfectly finished model.
TBH my rec center made the most soul crushing prank for me this year, because it was about building a cat park. The amount of people in the comments who were like "But can this please be real?" was amusing.