^Oh, I totally agree - and I stated as much in my previous post. I am in agreement with how the seating arrangements were handled on the actual day.
However - bending protocol and tradition is sometimes called for...like when Diana died (and the Queen returned to London - under pressure from the public - before she actually intended to return to London).
I think the monarchy would have been better served if Charles (next King) had been photographed on such a historic occasion next to the Queen. (And either Camilla rode opposite them or opposite them with Harry).
Charles is making inroads on the general public accepting him (I am not speaking here of people like you or I who follow royalty, but those of the general public that are only aware of the Prince of Wales in a very vague way). Charles received good - and wide - publicity lately with his weather forecast, his touching speech at the concert, and his delighted and warm reactions to watching the 'old' films and photos of the Queen. These opportunities will not occur again.
So I think there was a missed opportunity to present - and capitalize - on Charles in a yet another good and positive light (the next King riding beside the current Queen on the occasion of her Diamond Jubilee).
To restate: I understand the protocol - and think it's fine - that the seating in the carriages was handled the way it was. However, I think it would've better served the monarchy if Charles had ridden beside the Queen. Anyway, I'm digressing a bit from the forum topic, so better if I state future views on this in the more correct forum.