"A very unusual shunga image featuring a female with an unusual-shaped sex organ who is on display in a sideshow.”
Behind the woman one can see an exhibition poster. These kind of shows were not uncommon in Edo at the time but are very rarely depicted in shunga.
Reference: on p.201 (Fig.77) in ‘Japanese Erotic Art, the Hidden World of Shunga’ by Ofer Shagan
Original antique Japanese color woodblock. Shunga (Erotic picture).