Why would it be necessary for the robots to shoot from robo-breasts to be legitimate to have it female? They are male/female non-sexual robots IRL, like robots that help people find directions in Japan and such. It's just a random trait that relates to the design aesthetic. Just because it's female doesn't mean you need to be able to sex it. It's a robot for crying out loud! My girl exo has a robo-flower on her robo-head. It's fun.