At 22:20, Isobel describes Mary's new hairstyle as "Pola Negri comes to Yorkshire." Pola Negri (1897-1987) was a Polish stage and film actress and singer who achieved worldwide fame during the silent and golden eras of Hollywood and European film for her tragedienne and femme fatale roles and was acknowledged as a sex symbol.
The episode won an Emmy Award for Outstanding Hairstyling for a Single-Camera Series.
Mr. Molesey tells Daisy that he would like to help her with studies, but "not mathematics, obviously." He also mentions that he would like to have been a teacher. In Foyle's War ("Casualties of War"), Kevin Doyle, who plays Mr. Molesey, played a maths teacher.
During lunch, Mary mentions how the war had shown how half the population were badly housed. The poor fitness of many World War I recruits, resulting from substandard living conditions, and a dearth of affordable housing afterward led to the passing of the Housing Act of 1919, meant to offer government subsidies for the construction of hundreds of thousands of new homes. Additional acts in the 1920s made housing a social service.