The image must be drastically beautiful or else compellingly ugly. Jackie, Di, Barbra. These can be removed or peered over to offer an image of blinking vulnerability. Basic black attire is effective but must be Armani, never Gap. The face need never change, its very stasis a sign of rich inner troubles.
Sunglasses are superfluous.
They smack of effort. There must be a narrative structure that bathes the icon in the pure light of the fairy tale or morality play. Beautiful princess beset by ugly siblings or nasty stepmother. Lovely rich girl mistakes the charisma of power for true character. Prodigy singled out for great things at an early age by psycho father.