To many modern eyes this plate and others like it read as homo-erotic. It would not have been read so in Muybridges time. While the Victorians were extremely sexually prudish by modern standards and commonly considered male homosexuality a serious threat to their society they believed women had little or no sex drive. Therefore the possibility of lesbianism was commonly ignored.
Because of Victorian sexual taboos Muybridge was not able to photograph men and women naked together and was only able to publish images of naked men together engaging in sports or work. Because he was free to show women naked together he used female models when he wanted to show two people engaging in ordinary activities. In many plates he had one of the women assume a typically male role and these are the plates which today we tend to perceive as homo-erotic.