Tell, v. To give an account or narrative of.
To make known by speech or writing.
To give an account, description, or report.
To make known or indicate as if by language;
to bespeak. To disclose or reveal.

The Telling theme offers examples of portraits as narratives representing the various aspects of gender. It asks us to think about ways in which characterizations of female identity and of specific women depend on contexts (historical, mythological, others that you might think of.) — which is to say, how they depend on the stories being told in the background. They also ask us to think about how portrait images, themselves, can tell stories.