And you know this to be true because...?
Michael Cade Hughes is the "man" in that photo. Born a woman, she is a well-known tranny activist who writes for the Huffington Post. She took that photo to demonstrate what she feels is the absurdity of laws that segregate people into the restrooms that correspond to the gender they were born as.
So, if you saw "Ms." Hughes follow your wife or daughter into the ladies' room, what would you do?