Well, another day has passed and I didn't use Algebra once.
When Marie-Antoinette is going through her shoes while preparing for a big party you can see a pair of Converse All Star 1923 Chuck Taylor basketball shoes. While these shoes were definitely not in existence at the time of Marie-Antoinette, their inclusion in the film was intentional, to portray Marie-Antoinette as a typical teenage girl despite the time she lived in.