I just read that it’s a model of the real bookstore in Paris, Shakespeare and Company.
Now that you mention it... We went there once, but it was incredibly crowded so it wasn't such a great experience... too much of a tourist attraction. Many wonderful bookstores are a tourist magnet these days and most of them come only to snap a couple of pictures for their Instagram... sad..
I'm hearing Paris is especially bad for this when it comes to the well-known places/attractions. It is sad. That's the fate of so many tourist destinations.