Maybe the fact that I'm the only one mentioning this means I'm a little less intelligent than the rest of us, but...

Isn't a 'real' illusion one that causes you to see something that isn't objectively there? For example, The Grid illusion (http://en.wikipedia.org/wiki/Grid_illusion).

If you find an alternative way to create an identical image, then it's forgery, not an illusion.

Put another way, the Grid Illusion is to "worng sleplnig" what the Hollow Mask is to "conversation" (a word in both the English and French languages)