Are there any words synonymous with duality?

I'm writing a paper on Josef Albers. His artwork is highly illusionistic, which leads to the inability of the viewer to decipher the spacial planes of the artwork. Also, because of the ambiguity in his work (most of it is concentric squares) they can take on myriad meanings, depending on the viewer's own psyche. I'm trying to find a word the great many ways each piece can be interpreted. Polysemy is the closest thing I could find, but from my understanding, that is usually applied to written language.

Duality isn't extreme enough.