Do any of those companies actually have a live customer? Not a demo store, a real paying customer with more than one location live?

Standard.ai apparently has a demo store in SF, although it's been closed due to the coronavirus epidemic.

Grabango - one installation in test at a Giant Eagle store.

Getzippin - one installation in test at a Lojas Americanas store. Their site gives the impression that it's really about getting people to install their phone app, so they can be spied upon.

v7labs - we're AI, we don't need installations.