The photograph gives constant reference to the rectangle. This forces any idea into the confines of pictorial illusionism.
Dennis OppenheimTurning something upside-down elicits a reversal of content and pointing a steeple into the ground directs it to hell as opposed to heaven.
Dennis Oppenheim[The photographs] were there simply to indicate a radical art that had already vanished. The photograph was necessary only as a residue for communication.
Dennis Oppenheim