Leopard Optical Illusion (I just don't see it.)

I found this illusion on a website called "Delusion Illusion".  They don't reveal the solution!

According to the site:

"...it’s not some photo of an actual animal, rather a realistically painted picture.. But what is so, so good in this picture!?!   ps. this is one of the greatest delusions illusions!!

What's the illusion? 

If you can figure it out let me know.

Backyard Sky

Napoleon's Number Code

Napoleon used a number based code something like the one I like to use:

See Secret Code in Topics list.