Many thanks to all.
QAVION: My question is no more than idle curiosity as a semi-frequent paxer.
I was aware that engines are stabilised before t/o thrust is applied. Mainly due to listening to engines outside the window over 37 years as pax! My question was more of the time lag in the approach for go round. That has been more than satisfactorily answered.
On the occasions that I have been in the jump seat for landings, one has naturally been focussing on the view out of the window and observing the manipulation of the yoke - than thinking to ask about throttle levels. Of course, next time I am in the jump seat ... I shall probably need a jump wheelchair, so much time will have had to go by!
Thanks also Genghis for elucidating Spinning and Spooling.