Contrary to some expectations, most lounge receptionists I have spoken to at relatively low traffic lounges like the DXB F lounges or outstations actually remember the faces (if not the names) of their recent arrivals and if they have already brought a guest

And yes, which pax have logged into which lounge at what time by which receptionist is also recorded, as how will EK management know who to send warning letters to in case a pax misses their flight whilst officially being "in a lounge"...