Writing about web page http://crux.baker.edu/cdavis09/roses.htmlI was shown this today by a friend, and thought it quite interesting and blog-worthy, which my life generally isn't. While not wanting to brag, I got 'it' straight away, but then the comment further down the page of "smarter people take longer to get it" made me a little less proud. I'm generally quite good at puzzles though, so I think my brain might just be twisted enough to see strange things easily.
Another friend I showed this too had seen it before, so sorry if anyone else thinks it's old, but I'd never come across it.
Please don't give the solution away, the only hint I'll give is that a bit of lateral thinking is needed.