With the opening of its architecturally stunning new store in Tokyo, Prada has further blurred the line between art and commerce. In fact, the store, with all its accompanying hoopla, isn’t really about selling clothes at all. And of course, that’s entirely the point, at least in the minds of the Prada folks, who long ago realized that the best way to make people want to buy your product is to associate it with other impressive stuff, and then pretend that you don’t care if anyone buys it or not. Regardless of the capitalist aspect of the enterprise, though, the store is an artistic triumph, says Julie Iovine.