I wondered about that, too. Perhaps she followed the wedding tradition started by her mother. Her own wedding bouquet and that of the Duchess of Cambridge have been placed at the Tomb. But if that's what happened, wouldn't the coronation bouquet be visible during the procession out of the Abbey? And would the Queen Mother have laid her own coronation bouquet on the Tomb? Perhaps the bouquet was simply returned to the palace. Anyway, the tradition of giving each queen a replica on her coronation anniversary is lovely.