Director Niki Caro stated that her first film cut was nearly three and a half hours long, utilizing the entire screenplay. The final film was required to be two hours in length, and so an hour and a half was cut from the film in the editing room.
When the zoo animals are being "liquidated", Heck shoots an eagle and tells his aide to have it stuffed. Sure enough, when Jan and Antonina visit his office later, there is a stuffed eagle prominently displayed,
During the Liquidation of the Ghetto, the song that Urszula (Shira Haas) sings along with others at the Seder is "the Four Questions", often sung by children at the Seder, asking the adults the meaning behind the Passover Seder and its components.
This is the third film in which Jessica performs a character playing the piano. The first was The Debt (2010) directed by John Madden and the second was Crimson Peak (2015) directed by Guillermo del Toro. In Mama (2013), however, she had to be taught how to play the guitar for the needs of the horror film.