Picture the scene – a royal wedding, 1986. Princess Diana at the height of her beauty attended the wedding of close friend Sarah Ferguson. Many were disappointed with her choice of outfit, a blue silk dress with a black cumberband and polka dots. ‘She’s worn that outfit before’, screamed the press. ‘Its too low key for a royal wedding’ others cried. But this was the whole point. Diana wore something that was deliberately low-key and had already been seen so that she wouldn’t detract from the attention the royal bride should be getting. She let Sarah keep her spotlight. Go forward 25 years, to another Royal wedding, and a new…