Howdy,
Long story short, I reported a pic for being in the wrong purity level (SFW instead of Sketchy). While the pic was fixed, an admin did include a message in the notification asking me to please change the purity level myself in the future.
Unfortunately, I couldn't do that because the pencil icon to edit the Purity level was missing. I don't know if this is a feature or a UI glitch, but I've noticed that there are many wallpapers with disabled or non-functioning Purity edit buttons.