Detailed reading
How do you understand “the symmetry of the exhibition”? (Paragraphs 2) “The symmetry of the exhibition” means the balance, or the approximate balance between two sides: on the one hand is Marie Antoinette, the dedicator of the cellar and Queen of France to Louis XVI, and on the other are American pop stars. The former was royalty in history while the latter are royalty of the modern era, in the metaphorical sense.