As I was leaving the theater after a screening of Frederick Wiseman’s Ex Libris: The New York Public Library, the friend I watched it with turned to me and observed, “For a documentary about a library, that movie didn’t have a whole lot to say about books.”

It’s true that an institution as large and storied as the NYPL could furnish a half-dozen documentaries about everything from its identity as a vanguard public-private partnership to the architecture of its buildings before even reaching the topic of its holdings—some 8.7 million items in circulation, if you count ebooks, music, and movies along with physical tomes. This particular movie’s relative booklessness is noteworthy precisely because, at three-and-a-quarter hours, Ex Libris practically runs as long as a half-dozen shorter documentaries. If a movie of such great length isn’t asking us to think so much about the holdings of the library, then what is the point it’s trying to make? Par for the course with Fred Wiseman.