Personally, I never get tired of watching videos about how giant warehouses operate. Ever since my first in-person experience visiting Chronicle Books' warehouse (prior to their relationship with Hachette) up in Reno, NV many years ago, I've been enchanted by the size & scale of how publishing companies deal with both big and small orders.
This video from one of my client publishers – Oxford University Press – will show you the tall racks with multiple levels of pallets, as well as the smaller shelves with individual piles of books. 4.5 million books in stock at any given time! That is a lot of books.
And they mounted a camera on a box on the conveyor belt! Awesome!
Thanks for the tour, OUP!