The Flag of the Union should be displayed with the thick white parts of the diagonal cross nearest the flagpole above the thin white parts. The way it was displayed (as seen in the picture), with the thinner parts uppermost, was historically used as a sign of distress or a coded warning of trouble in times of war.
A check of my Hot Toys 1/6 scale 12-inch British Army's Blues and Royals Regiment figures confirmed that I'd place the UK flag/insignia correctly. Wouldn't want to disrespect anybody nor any country.
These British Army Blues and Royals figures are aptly named "William" and "Harry" by me :)
Hot Toys Blues and Royals Regiment Tank Commander reviewed here
Hot Toys British Army Blues and Royals Regiment Lieutenant in Afghanistan reviewed here
Action Man's Blues and Royals in ceremonial attire reviewed here