If you type Diamond Jubilee Thanksgiving into youtube you'll get a variety of videos, the entire event hasn't been posted anywhere.
It seems like it is you who is ruining the occasion for yourself, you've taken it upon yourself to highlight in your own mind Camilla sitting in that position when you could have just ignored it and focused on The Queen. It was a last minute decision, hence the original arrangement of three carriages instead of two.
I believe Camilla's hat was the same size and HM's just a different style, something Camilla has adopted from HM is that the public like to see their royals so hats with upturned edges are a very good idea.
Actually, Charles has never actually admitted he wants to streamline the royal family, this appeared from the press and stories about Beatrice and Eugenie, it was The Queen's decision to make the balcony appearance as it was and I am under no impression she was lobbied by anyone. If she doesn't like something, she won't do it. We know this from the numerous personal interviews we've seen these past two years