It’s 2008. I’m ten years old. I have a henna cone in my hand and I’m not afraid to use it. I squeeze unrecognisable flowers onto the women, and I paint wonky footballs and messy rockets onto the boys.

Sitting at a small table in the Firehouse, a funky art collective not far from the downtown Phoenix campus, 23-year-old Joanna Lockyear squeezes brown paste out of a tube onto a girl’s skin. With sure ...