  :::::The graph is relevant to the identity, and it does help some readers. This article is visited some 500 times per day, whereas we have three people on the talk page who don't like it and three who do. Hardly proof either way. :::::Also concerning OR: There is another tacit agreement that images require extra leeway. I would be surprised if the diagram were found in a textbook aimed at an expert audience, even more than I'd be surprised if a randomly chosen sentence from the article turned out to be a quotation. Now think about the content: it's half a unit circle with an arrow on the end for crying out loud! We're not talking about a conceptual revolution over here.   