The third one, I try to prove that stucture is an important element in communication that could effect a sign's meaning.There is some relations between sign and its enviroment surrounded. 
Still the transsexual toilet sign, in this scene, there are there doors(All imgs, left one is the real situation, right side ones are my recreations ), if there are a boy symbol on the left the girl symbol on the right, the transsexual in the middle, it's quite clear that there are three toilets for man, woman, and transsexual.

What if, like this, there is only one door(some restaurants,bars may just have one toilet ), in this situation, the tran sign could be a sign symbolized it's for everyone regardless of gender identities.
Or toilets like this(of course this photo is not a toilet ), there is a tunnel, one side is man others is woman, what if I put it in the middle on the wall but no sign on each sides, How do people read the same sign? Whichever? not matter who your are you can use both sides? Or still left is man, the other is woman?

Then I put the sign in different places to see what meaning I can get.

Also, in the same place, what if I put is in different place.

I wanted to do this because of several real design works as follow:

They use space as a part of their commucation.

All experiments I did is trying to find a better communication way.Simple is a good quality in a design work, but emotion is also indispensable.