In this drawing, the prisoner portrays himself as nude on the waterboard, immobilized as water pours down on his hooded head, his right foot contorted in pain. The image contrasts with some others seen in popular culture; an exhibit at the Spy Museum in Washington, for example, shows a guard pouring water onto the face of a prisoner who is neatly clad in what looks like a prison jumpsuit.

Mr. Zubaydah’s self-portrait also shows a design detail not present in most depictions — a drop-down hinge to tilt the prisoner’s head. Restraints hold down his wounded thigh.