Waterwork

"A video camera is suspended from the ceiling, its lens pointing down. Directly below is a linked monitor on its back, facing up. The monitor is encased on all sides in a metal box, the top is open. Above it is a glass tank, filled with coloured water or oil.
The viewer, on looking into the tank sees him/herself face to face in the fluid. Simultaneously another image is seen on the monitor below - the back of his/her head, looking into the tank." (Source, sité depuis le site web Rewind)