Emoji crown can refer directly to this subject. Royal power or its direct delegate (king or queen).
It does not have to be the person wearing exactly the same headdress. This can mean any monarch (Mongol khan or Egyptian pharaoh).

The idea of designating your higher status with a more lush garment is as old as humanity itself. But utmost attention was always given to decorating the head. A crown of feathers, a plume, a huge cylinder height. The person with the highest status should always have the most luxurious headdress. Crowns were made by the best jewelers and decorated with many gems.