Try to figure out what shade of grey the moving triangle really is as the person moves it around the page.
I have loved optical illusions since childhood, and I think the simpler ones are the best.
You don’t get much simpler than moving a grey diamond around other grey diamonds, now do you?
The music may make you feel like there is something a bit mystical going on, but…
There is actually a scientific (and incredibly simple) reason why the moving diamond blends into the other diamonds that it is passed over, but I’m not going to tell you.
You will just have to figure out that one for yourself.
