The building has sixteen apartments. There is nothing outside the building. Apartments can communicate with those above and below them, but can only look at the apartments beside them. Apartments being looked into do not know that they’re being looked into as the apartment that they look into is not the one looking in at them. Adding to the complexity is the movement of the apartments; apartments on higher levels can descend and look into the apartments below them without those apartments ever having knowledge and likewise those lower apartments can look in at those lower etc… This activity can result in having the highest apartment looking into an apartment that is observing another apartment that is observing another apartment that is observing another apartment. The difference with the last apartment being that it is unable to communicate with the four apartments who are observing it and its most immediate observing apartment is unaware that the apartments above are able to descend, as is the case with subsequently high apartments, although they, including the top-level, acknowledge the possibility that apartments higher than theirs might be observing them. The situation would deteriorate if someone in the apartments above was to tell a resident below that they were being observed. Another wrinkle is that the bottom apartment can change its perspective by moving to a different position on the grid which in turn changes the default perspective of all the apartment above it.