- Yes, normal shelves.
- "Contents" are the items on the shelves, the products for sale. Obviously, they can't actually talk but in this writer's vision they can.
- "Razors" - yes, normal razors for shaving.
- This writing could be science-fiction, fantasy or just normal fiction.
The only thing I can think of is that some kind of computer system has been put in place in that supermarket which means that some software on the shelf links with the products on the shelf and counts how many of the product are removed and presumably sold.
So, in the morning, there are 20 razors on Shelf A1. During the day, 15 people take one razor each from the shelf. Somehow, via a computer, the shelf recognises this and records that 15 razors have been bought. The staff then ask the shelf software for updated information and it tells them that there were 20 razors in the morning but at the end of the day there are now only 5. So the staff now need to order some more razors to put on the shelf.
Perhaps this is actually happening now but I haven't heard of it.