I just found this video linked to on The Royal Corospondent. It's a video from 2007 of Caroline Weber, author of Queen of Fashion: What Marie Antoinette Wore To The Revolution, giving a lecture at the University of Michigan on the topic of Marie Antoinette's "sartorial semiotics." In other words, the significance of the fashion that Marie Antoinette used to create a political identity. It's a really good overview of her book, distilled into 50 minutes or so of discourse, with questions at the end (though, spoiler alert: She sadly does not give us the Lacanian analysis of the pouf hairstyle).
I also came across another interesting vlog that Dr. Weber recorded talking about the comparisons between pre-Revolution France and modern American fashion:
If haven't already bought the book Queen of Fashion, I just so happen to have a brand new hard copy version for sale on Half.com. It's a fantastic book, very readable, and a very different take on Marie Antoinette.
