Dear Ark. Please try not to bite when I have a little dig at the light blue. It is a Jack to me as that is what it was first designed for. It is a flag when flown by an Admiral of the Fleet. A not very likely occurence now. (RM establishments use the White Ensign these days.)
Of course it is also a flag when dressing a coffin. There were rather too many of those on tv today as well. Lets pray that we won't see many more.
Back to my original post. My daughter thinks the little golden objects on the British poles were Golden Snitches. So nothing sinister is intended by the USA or RAF. It's just a plug for the new Harry Potter DVD out on Friday.