Maybe it's because I'm also in retail IT and have seen similar models, but I get it. At the risk of oversimplifying, they've got two problems - code written in an office somewhere has to run identically in 2000 geographically separated places, and it needs to do so with some level of protection against failure. All other K8s gloss aside, it's a good way of making sure that there are multiple instances of a Docker container running. Assuming they set the cluster up correctly, they can suffer hardware failure and not downtime, and assuming they're using those little nucs in the photo, they can do so for under $1500. Sure a single server-grade piece of hardware would probably do just fine and have similar protection from failure, but this is essentially that on commodity hardware.