They are sitting behind the "cage" which fronted the street for all to see (and choose) within the licensed quarters. Shin-Yoshiwara was a famous red-light district of Tokyo. Note that they are not geisha. (Geisha were not prostitutes.) This photo was taken during 1907-1911. The woman in the far back was the brothel's matron who supervised this live display and everything else. In 1912 when Emperor Meiji died, this live display of women was later replaced by framed photographs of each woman hung near the brothel's entrance. In 1958, prostitution was outlawed in Japan, and Yoshiwara was history.