When Anthony and the Duke are talking, right before they fight, the glass of beer that Anthony is drinking changes amounts.
During the queen's luncheon, the musicians are not actually playing their instruments. The violinists bows are held over an inch above the strings.
When Marina is making her 'tea', the kettle whistles. The whistling kettle was not produced until the early 20th century. Besides which, this is clearly not a kettle with a whistle.