Sharp, whose long face looks a bit like Prince William’s, was standing outside on the sidewalk fielding questions from colleagues and a stream of smartphone missives from his chief collaborator on the project—the movie director Wes Anderson, the installation’s headliner. According to Sharp, Anderson was squirrelled away on the other side of the Seine, writing a new screenplay, but responding to texted queries and photos, and biking over periodically for brief inspections. (Fans of Anderson’s movies and their retro detailing may be disappointed to learn that he rides a perfectly modern high-tech sort of bike, not a vintage Schwinn or an iron-and-wood velocipede.)