Actually, that would be easy to miss. How often do you use restrooms on any floor other than where your desk is at? Perhaps if you attend meetings on that other floor, but otherwise, probably not.

The showers at my office are in restrooms that are on the lowest floor of a 3-story building. With 450 employees in the building, there are lots of restrooms. Since there are no meeting rooms near the showers, most people have no reason to use those particular restrooms.