What does Drioli's Back Tattoo represent?

Drioli’s back tattoo represents his devotion to art and to his wife. Tattoos represent permanence, so the fact that Drioli allows Soutine to tattoo him shows that Drioli is entirely committed to Soutine’s art. This is evident because tattooing is a form of art. Moreover, the subject of the tattoo is Drioli’s wife, Josie, which highlights Drioli’s devotion to his wife.