The first reversal *spoilers*
I really liked the cheekiness of the reversal 1/4 way through the movie when the filmmakers reveal that the "caper" that just occured was not real. It's a great postmodern commentary on how the perfect heists of previous films are unrealistic. The discussion of the public vs. the private Shahbandar reinforces the idea that the media (in Shahbandar's case, a magazine story) has a tendency to misrepresent reality.
The reversal is also a wonderful bit of characterization for Nicole. The Nicole of the dream-heist is beautiful, mysterious, unfailingly elegant. But she never so much as speaks. She is "perfect," but only because she has no real personality. As Harry says, this allows dream-Shahbandar to project his image of his wife onto her. The viewer is also left to decide who Nicole is; she is just as much the viewer's fantasy as she is dream-Shahbandar's. The real Nicole, on the other hand, ends up looking flighty at first because she contrasts so strongly with the ideal Nicole. However, when the real Nicole's personality really starts to shine through, she proves to be a wonderful woman: modern, knowledgable about the arts, moral, and above all, caring. She is better than "perfect." She has demonstrated that she is as "beautiful and pure" as the princess who inspired the bust. And in a movie where women are clearly socially subservient to men, the fact that the real Nicole is better than the ideal version is a wonderful feminist statement.