Curious about the "no derivatives" license. Surely anything derivative would be of the original now public domain art and not this. I do not see how this could as a practical matter be enforced. IANAL though.

Public domain isn't "viral" like copyleft.

If I take something in the public domain and make a derivative work, the original remains in the public domain, and I retain ownership of whatever additions or modifications I created. So I can attach whatever conditions I want to the copying of those additions.

For instance, Disney's "Sleeping Beauty" was protected by copyright when it was released, even though it was based on a centuries-old fairy tale that was in the public domain.

Well not if I take this 1 bit image and add my logo or remove his...