In 1907, the photographer Alfred Stieglitz was sailing to Europe in first class. Walking on deck, he looked down into the cheaper "steerage" section, where poorer passengers were packed together, and saw shapes: a gangway, a funnel, a staircase, hats, shawls, laundry. He rushed back to his cabin for his camera.

He had one plate left. He took the picture.

Stieglitz later said he had seen it as a pattern of shapes, a picture "of shapes and underlying that the feeling I had about life". It became one of the most important images in the history of photography, helping prove that a photograph could be art and not just a record. Picasso is said to have admired it.