Ambiguous images may have an enduring appeal because of this, articulated as "The Beholder's Share" by the art historian Ernst Gombrich where the viewer participates in the conceptual completion of the work of art by drawing upon personal experience and expectations, and derives enjoyment from it. (There's a smattering of flattery involved too.)
It's not only what is said, but how it's said. And in Ambiguity's case, what's said is said obliquely. Ambiguous images walk the tightrope between being not quite clever enough, and so obscure that no-one gets it.
Ambiguous images fall broadly into three categories:
- soluble - the key to resolution of the image is embedded in the image, no external reference is necessary (but a prompt to keep on looking for the unlocking key may be provided, for example, in the image title). This is common in delay.
- assisted - ultimate understanding of the image requires information outside the frame perhaps via an explanation of the image's context in a description provided.
- unresolved - deliberately devoid of key or explanation to leave the viewer in suspense.