I'm with Old Man on this one well put BTW, even here in Seattle there is a sculpture under a bridge in a fun part of town called The Troll, thing is copyrighted not even a paper cannot run a photo of it without paying a fee. Often Clip Art is public domain (Mickey Mouse was set as a slew of other old images to become public domain but thanks to a few lobby people and big bucks it was extended) unless it's packaged into something else and then have to read the rules. Dali was a painter as was the Mona Lisa a painting, did he copy it in a sense but it is only one element in the entire painting you'd have to see them real life to understand an Artist viewpoint
Peace