Zizek seems to be arguing that were we, the everyman, to fully comprehend the 'reality' of the exchange farce, "the effective act of exchange would no longer be possible" (p 20). That we cannot grasp its scope and depth is essential to its veil, he claims -- certainly echoing the likes of Jameson and Baudrilliard on the tactics of postmodern forces in ensuring our complacency. I have a few issues to take up with the politics of this claim.
Given Zizek's discussion of Marx's unfinished treatment of "the material character of money," it is interesting to consider what separates us - in this 21st century multinational iteration of capitalism - from the very exchange value system of which Zizek speaks (p 18). Zizek is interested in the ways in which the value of money is abstracted from its actual material form. Yet we currently reside in a moment when tangible gold-standard transactions are expired.