I observed some things over the years, cleaning those bathrooms. If I "closed" the women's washroom, it was far more likely for a woman to knock on the door and ask to use the bathroom. If I "closed" the men's washroom, it was common for me to pop out when finished and find a man waiting sheepishly.
For clarity: I only closed one at a time. Once more: there was nothing different between them. The Starbucks I worked at then was not a particularly busy location. It was rare for there to be any kind of queue for the bathrooms, so more often than not the other bathroom would be available for the knocking-woman or waiting-man.
If I popped my head out to get a cleaning supply or more toilet paper, and if I saw a man waiting, I would let him know that he would be welcome to use the women's washroom. The man waiting would often respond with visible relief, but usually verify: "You're sure that's okay?"
"Oh yeah, absolutely. There's no difference between the two."
And he would go to use the bathroom. As though waiting for permission, even though he probably already knew there was no real difference between the two bathrooms and no real reason to distinguish them.
When I opened the door to a knocking woman, she would often look slightly panicked and ask why she couldn't use the bathroom.
"I'm cleaning it at the moment," I would say. "I'm sorry for the inconvenience, but the other washroom is available if you'd like to use it. Or, you can wait."
Sometimes, the woman would nod her head and also respond with relief. Off she would go to use the empty bathroom and I would return to my cleaning.
Other times, the woman would nod her head and opt to wait.
And then there were the women who, shall I say, panicked.
"But that's the men's washroom!"
"Right now, it's empty. There's no difference between the bathrooms. You can use it, if you'd like."
"I can't use the men's washroom."
And then there was the woman who demanded I vacate the women's washroom immediately so she could use the toilet. I had never seen someone so flustered at the idea of using the "wrong" bathroom. In the time it took me to get my cleaning supplies out of the bathroom, I'm sure she could have used the other bathroom and been finished.
I remember she said as I scurried out of the bathroom: "The least you could have done was hurry up."
I guess I could have. I guess I could have started covering up the signs when I began cleaning.
At the bookstore, no one seemed to have any trouble using the other washroom and those were multi-stall and did have urinals (and strangely distinct smells).
I wonder why.