Originally Posted by corporate-wage-slave

Yes, it is exactly that, as you come up the escalators from the bus, you first come to the UK Border, which you would previously pass en route to Flight Connections. You can use the e-gates if you hold a EEA or Swiss passport, or are covered by the Registered Traveller scheme. They are extremely quick to get through, I rarely wait more than a minute to get through them. If you don't have such a passport, try getting into Fast Track Passport, by showing your AA card and boarding pass.