Before Iowa Stubborn, a nail that holds up the flag decoration disappears and reappears from time before the song; it's the nail closest to the ladder on which stands the man with the mustache.
When Marian is walking down the street singing "My White Knight," her purse moves from one hip to the other and back.
Marian mentions ordering the Indiana State Journal of Education for 1901-1910, but when the book arrives, it's clearly labeled "1890-1910."
When Prof. Hill retreats to his hotel room to pack, the floral patterned curtains are drawn. However, as he's singing in response to Marion's soliloquy, he approaches the hotel window and the curtains are now laced panels and are opened.
Each book in a library has a "call number" on the edge or spine of it, which identifies the book's subject. In the movie's scenes that take place in the town library, it's easy to see that none of the books have call numbers.
In a few scenes, "modern" (post-1959) 50-star American flags are visible. Official designs available between 1908 and 1912 (the time of the story) would have had 46 stars.
During the number, Iowa Stubborn, a bald, older man is pictured holding a pitchfork, while a dour-faced woman steps up from behind him. Together, they pose for a brief moment, creating a vignette of the famous painting, American Gothic, by artist Grant Wood.
However, that painting was created in 1930, whereas this film takes place in 1912.
However, that painting was created in 1930, whereas this film takes place in 1912.
At the end of "Sadder But Wiser Girl", the piano player's fingers strike the piano keys after the last note is played... showing that the piano player is acting like he is playing piano. Also, at the beginning of "Sincere", Ewart Dunlop does not start singing when the rest of the quartet does.