A dozen people in winter coats stand with their backs to the camera while a guide talks. Above and behind them, eleven or twelve paintings crowd a single wall in two and three loose tiers, tondos beside rectangles, wide frames beside narrow ones, a Chagall village floating at the far right with its white horse and its enormous eye. Nobody in the photograph is looking at the same picture, and several of them are looking at the guide instead.

The wall label gives the date with unusual precision: Paris, June to July 1914. Francis Picabia was working on a canvas over eight feet tall, filling it with pistons, tubing, gears and flesh, while the Austrian archduke was shot in Sarajevo and the ultimatums began moving between capitals. He finished it, or stopped working on it, at roughly the moment Europe committed itself. Within weeks he was in uniform. The painting is called I See Again in Memory My Dear Udnie, and it hangs at the Museum of Modern Art in New York.