This might be a play like the old Crown Books stores which sold only best sellers at a big discount with the idea of making it up on volume. But Crown did not last long. Amazon does have good data about what people buy, so perhaps they could maximize revenue per square foot by packing popular sellers in. On the other hand, one departure of this store from typical bookstores is that books are all facing out on the shelves, meaning fewer titles and probably less revenue per square foot.
I'm wondering how this approach to bookstores could pay off for Amazon, except by putting competitive pressure on any other bookstores in the area. But Barnes and Noble closed the store it had in this shopping center quite some time ago. Is it advertising, an attempt to upscale Amazon's brand? Amazon has the number one favorable brand among consumers from what I've read, and it's certainly where most people go these days for books -- last report I saw said over 80% of book buyers use Amazon. So what the business purpose of this store is, unclear to me. But it's Amazon, and surely they're just a few steps ahead of what I can see.