To get a bit more specific, this Recode article has actual pictures from inside: https://www.recode.net/2018/1/21/16913984/what-does-photos-a...
The store has a bunch of ready-to-eat and semi-prepared bundles that hit a very narrow niche in the grocery market. There are a few pre-packaged name-brand products, but everything is arranged in a highly regimented manner, and the store is very small. It's revealing to note what's missing: any fresh produce whatsoever.
What I'd rather see from these articles is a bit more of a critical eye on the claims. Does the company actually think they could leave the store open with no employees present? Do they even have a reasonable premise that fewer cashiers even means fewer employees? (Someone needs to be there to help people who don't have the app, or to watch that no one jumps the turnstiles, or to keep the place clean, or to restock the shelves.)
And what about the software itself? Do the cameras keep track of the inventory correctly? What if a customer puts a product back down in the wrong place? How much awareness does the software actually have? Is it tracking your phone or you? Does it attempt to deal with scams (can you bring an empty boxed meal kit into the store, replace a new one from the shelf with the empty, and then walk out)?
Maybe these aren't big concerns for this single store, but they are huge concerns if you want to scale this to compete with 7-11 or Pret a Manger, both of which, I will note, have more fresh fruit available for sale.
Now, I don't think Amazon is really thinking that sort of thing is imminent, or that they are actually going to make money from this store. This is a vanity experiment, nothing more. They are getting lots of free advertising from a credulous press, and that's plenty sufficient for them.