FTG
That's not very helpful. I'm sure that the OP is just asking about.
I'm wondering about which isle it was - (IOM?), and what the trolly pusher was doing there.
Leaving that aside, the answer is that the trolleys need to be pushed in a certain sequence in order to maintain the correct balance of the aircraft. A sensor attached to the trolley calculates the weight added to, or taken from, the trolley. The pilots can then operate the trim wheels to keep the aircraft in level flight.
It is expected for the cabin crew to be thrashed with a birch if they fail to observe the carefully-rehearsed sequence of trolley movement developed during preparation for the flight.
There will be a call button near your seat, and you may use this to indicate that you need to visit the lavatory. A cabin crew member will attend to you and alert the flight deck to the temporary change in the aircraft's CoG. You should also mention whether it's a wee-wee or a do-do as this can be critical.
HTH,
SO