How do I interpret the admin "Network" page?

I’m sure I’m being dense, but how do I interpret this page:

There is a little more info here:

It just shows some information about the devices on your network (or at least the ones the Pi-hole devices knows about).

I’m confused about the “Uses Pi-hole=No” entries. This seems to imply that ads are not being blocked for those IP addresses, which is plainly not the case.

Those IP addresses have not made DNS queries to Pi-hole (at least not directly), so they are marked as not using Pi-hole.

It might be that your router is being used for DNS by you clients and then forwarding all of the requests to Pi-hole. In that case, it is impossible for Pi-hole to know which clients are querying it, besides the router.