The long title for this image is:-
"An Evening Walk during Night Closing of Refracting Mirrors on the Islands of the Gods" This is an image of the interior of a very large cylindrical space colony. It has three strips of skylights. The Earth is about to be eclipsed by one of the three refractory mirrors of the space colony outside the skylight. Nothing 'falls down' within the colony due to the whole structure rotating slowly. Lights can be seen from buildings on other islands. Dwellers on the colony would have to get used to the fact where ever they are, on either side of them, the land and sea curve to either side of them and up over their heads, so that on looking up they will see things which look 'upside down'.