Wikipedia: “The original Fountain by Marcel Duchamp photographed by Alfred Stieglitz at the 291 (Art Gallery) after the 1917 Society of Independent Artists exhibit.”
Another passage from Kay Larson in Where the Heart Beats: John Cage, Zen Buddhism, and the Inner Life of Artists:
But its actual title in The Blind Man was Buddha in the Bathroom. In Stieglitz’s photo, the bulbous porcelain body looks exactly like the Buddha in outline. (Duchamp must have instructed Stieglitz to aim the camera from a certain angle, since other photographs of the urinal don’t resemble a Buddha.) The white porcelain arc serves as the Buddha’s robe. Where the Buddha’s head would be is a bright white spot that could represent the “third eye,” one of the classic attributes of enlightenment.
The Blind Man refers to “a little magazine Duchamp and his allies [Henri-Pierre Roché and Beatrice Wood] put out.” [That’s quoting Larson.] You can see scans of the issue in question here.