A project I’ll never do and If I do…

At the same time, two persons go inside two different houses, buildings, places with windows facing each other, no matter how far from each other. They go inside. They walk towards the window facing the other person’s window. Once both persons are in front of the window, they wave hello to each other (even if their chosen hoses, building, places are too far away from each other to see each other) (if they see each other it’s ok too). They repeat this action in multiple spaces, in multiple days. Without documenting it. Without telling about they doing it.