They have 4 large LCD screen in the centre of the rooms, facing outwards. These screens only show how many people are on the phones and how many customers are waiting. This display is updated every 15 seconds.
A large e-Ink display would be perfect for this. There is no colour needed and should save a fair chunk of power. That is, of course, I'm mistaken about the energy usage of e-ink displays?
Surely someone has created one if that is the case? Surely there would be a market for it now? And if you needed a bit of colour, I'm sure basic colour e-ink displays can do the job fine.