I think you can either see it or you can't. I looked and looked and could not see. I asked Meade, and he took one look, said — in one word — what it was and then I immediately saw what it was — quite clearly — and now find it hard to relive my mystification.
Via Metafilter, where some people are making some good jokes like "Seriously people? It's BLUE" and "Who is this Rorschach guy and why does he draw so many pictures of my parents having sex?"