No, these aren't painting. They're hi-res shots of Operation Canopus, and French nuclear test conducted on August 24, 1968 at Fangataufa Atoll. Strangely beautiful and completely terrifying all in one go.
This one is my favourite:
I think it's something to do with how the clouds are parting to make way for the mushroom cloud. The explosion is like a giant middle finger aimed at God. And in an abstract sense, that's pretty much what nuclear weapons are. You destroy us? We'll destroy ourselves, thank you very much.
For more shots at much higher resolutions, check out the Flickr Stream.