The Mirror refers to the new Terminal as "swanky" & "swish"...
Reference East Security upstairs this appears to be totally extra security area which will be available & in addition to the existing security area which will certainly be re-named West Security as if the fly-thru video is freeze framed at 1.22 there is a yellow departures information column with "How busy is security"? indicator for East & West.Yes there is a Premium security gate at East but along with a normal entrance.
Interestingly too in the new Arrivals Terminal from immigration it is a descent via escalator to baggage reclaim/customs & Arrivals Plaza.
Gone will be the days of the original concept & design of a one level STN.