All artists are illusionists of one kind or another.
By merely increasing or decreasing the amount of contrast in any area we can move the observer through the painting.
Realistically there is no limit to the possibilities. How does an artist make decisions?
The way we see is critical to understanding how others will read our compositions.
A painting with a message does not happen by accident. It happens when you place elements in their order of importance.
That a viewer does not see what the artist intended does not make the composition a failure... In reality all artists speak first to themselves and then to an audience.