SOAP
They don't know which items have to be removed from luggage for scanning.
What are you talking about? When did you last have to remove items from luggage arriving at T1 Border Control?
The caterwaul that was shouting last night sounded like she was angry about having to do her job, hated people (without whom it seemed her job would have been so much more to her liking) and she just made the whole environment unpleasant and, I surmise from some facial expressions, a little intimidating for those not used to the place.
I stand by the opinion that 'shouty person' is totally un-necessary since as you enter the area you can only go one of three ways: EU / Non EU / E-GATES all of which have enormous signs telling you where to go.
Get that woman sat behind a desk checking passports - that would speed things up.