Have you ever thought about what the bathroom stall is? I thought about it today. It is a borrowed room, for sure, and best of all, for a short time, it is yours. You have that space occupied and no one else can enter. You can engage in private business without someone hovering over you, if you so choose. If you want company I'm sure there are those who would be willing to come along, though I don't know why someone would. There are some sick fucks that place cameras in the stalls, but for the most part we occupiers of small spaces are alone. No one watches as you squeeze out a nice turd for the porcelain throne.
If I take that last metaphor a little further I could say that one is king! Your country is very small, and you probably won't be hosting any heads of state, but it is yours. Don't go invading other countries while you're there. Nope, no sticking your foot under the the wall. Nope. That would be a means to get your own kingdom invaded by the monarch next door, and he/she is not likely to be pleasant about what they say or do. Who wants an invading foot crossing into their territory? Invaders shall be repelled with hostile words and foot stompings!
Some people have writing on the walls of their kingdom. Consider it corporate sponsorship. There are advertisements to 'Call Lisa for a good time at 555-4455'. There are sometimes political messages, like 'Bush Sucks balls!' or 'Monica Lewinsky was here!' There are sometimes even cartoons of one sort or another, though they're usually of penises or something of that nature. No one ever became well known for their stall art, but that doesn't mean it couldn't happen in the future. Maybe one day Lisa will become famous for the services she is reported to provide. You never know. Elsewise it is entertainment for the monarch of the minutes and none other can deny that enjoyment.
The worst thing that can happen is that the country runs out of toilet paper, or the throne floods. Natural disaster do happen! If the throne overflows, and a sea of alligator execrement flows onto the land, there's nothing doing for it but abdication. Give up the throne and fly far, far, far away in search of your next kingdom, your next territorial expansion!