A screen’s Overview is where you check what hardware is on the other end, and it was telling everyone the same thing: every Screenly Player Max read as a Mk1, with the Mk1 photo, whatever revision it actually was. Raspberry Pi based screens had the opposite problem, showing no board revision at all.
Both now read what the player itself reports, so the model name and the photo on the device card match the hardware in the room. If you have a mix of Player Max revisions across sites, the Screens list is a reliable inventory again.