It’s not what it seems...
‘Automated facial recognition’?!?! You’ve fallen for the techno hype. The reality is spelled out here:
while a camera takes a picture of the traveller and an officer at a control station behind the gates checks that the image captured by the camera matches the one on the passport (facial recognition).
So they have 1 person manning multiple gates, so the delay is that person checking the other photos before yours.