It's possible you cannot see the illusion ~ but that's the answer to that issue. Somethings can be seen going two different directions with no change whatsoever needing to be made to the image.
So, the question is do you understand the illusion or don't you?
Sorry dude. I deal with reality, science and nature. Artsy Fartsy stuff put together by leftist pinheads is a waste of time. Got to bail. Have fun. Will check in tonight. The bottom line is light physics. Not a very difficult subject, but not taught to a lot of people. If you know light physics, you know it was heading west at a 45 degree angle. Exactly as the General implied.