I don't know GLA well, but I seem to recall that the domestic departures area is exclusively for domestic passengers, so there's no need for the photo routine. Everyone is already "inside" the UK.
Oddly enough the domestic pier is kept seperate so that once you leave the lounge you can't return. I have never been able to discover why. If your flight is delayed you are stuck out there or if you forget something you need to buy you're screwed. EDI doesn't have the same issue.