With the Weekly Photo Challenge of “edge”, I was immediately drawn back to the great Terry Prachett..
The disc, being flat, has no real horizon. Any adventurous sailor who got funny ideas from staring at eggs and oranges for too long and set out for the antipodes soon learned that the reason why distant ships sometimes looked as though they were disappearing over the edge of the world was that they were disappearing over the edge of the world.
This photo, which was taken in Prague, to me just looks like penguins disappearing over the edge of the world in an orderly fashion.