PracticalAndrogyny.com explains why the Necker Cube is the perfect symbol for androgynous gender presentation:
The Necker Cube is symbolic of the androgynous individual’s physical ambiguity. Regardless of whether we identify our genders in the terms of a gender continuum, as being without gender or as being something else entirely, the Necker Cube symbolises the ambiguity we present to a world that is primed to see all people as one of two binary options. Androgynous people can be taken as female, male or as something else entirely but, like the Necker Cube, our ambiguity invites those who interact with us to question what they see, and perhaps strive to see the true picture.