Socks and sandals is a sin.
I think you're dead on with the famous part.
Before mass media, fashion changed slowly and in little pieces.
Like you could wear 1750s clothing in 1800 and just omit the wig and you'd still be fashionable.
Whereas in the modern day if you wear a suit with a cut from the last decade, you instantly identify yourself as either old or lacking fashion sense or both.
Mass media helping fashion trends spread doesn't necessarily mean that famous people are the ones spreading fashion. Any old random Joe could start a new trend if his picture got passed around enough nowadays. In the 1750s, on the other hand, pictures, videos and such weren't available and thus fashion trends took longer to spread because it was by the slow word of mouth.
Mass media is unconcerned with Joe Random and his forward thinking use of old soda bottles as hats. And I don't think social media would treat such a thing as anything more than an amusing meme photo. If Peggy Debutant made a hat out of an old soda bottle, that would be newsworthy.
...oh thank god someone agrees.