Since Kate Middleton married royalty and became a Princess (or, a Duchess... or Lady... or whatever) it was socially acceptable for her to wear a tiara at her wedding.
But if I wore a tiara at my wedding?
I'm not hoping tiaras become fashionable any time soon. I'm just stating the obvious differences.
I will continue, however, to wear my plastic tiara in private because I think it makes me look classy.