Sounds like you had a good day out
It seems many of us seem to not notice the chelski hat
But the old bill is not quite a waste I dont know the numbers there but if Like hounslow with 30k in quite a small area I think the police were there for the usual what if it all goes pete tong as are the other emgency services.
At Hounslow in the food area if there had been a fire or someone trip over one of the families siting in the walkways there was a chance of a stampede or crushing
Also sadly i would not be suprised if they are not there to ensure no wholesale gatecrashing of the event or pickpocketing goes on..
I remeber thinking Hounslow would have been a pick pockets dream with everyone so relaxed and at ease..