This is a non safe for work, as in lewd, instance.
It’s safe to assume that anything you see here will be lewd.
Just letting you know. If you view the content and then pull a surprised pikachu when you see big anime tiddies, Judy Hopps getting railed or some furry vore… Then it’s on you.
Should this popup continue to show up, you may want to enable cookies or disable privacy focused addons on your browser, I assure you we won’t track our user.
Should that fail, some users claim they got rid of it by hammering the ok button.
I guess it switched desktop environments on you? If you’re logged out there’s supposed to be a way you can switch between desktop environments. It makes sense that the GNOME Settings app would only change wallpaper settings for GNOME, which I think is the main Ubuntu desktop environment. Are you sure you didn’t upgrade to a version of Ubuntu that uses XFCE instead of GNOME?