At approximately 39 minutes, the black and white film they are watching is Le Dernier Rivage (1959), a movie about the end of the world starring Ava Gardner and Gregory Peck; Peck's real life grandson, Ethan Peck, plays Augustine's (George Clooney's) younger self.
Felicity Jones found out she was pregnant after being cast, and George Clooney simply rewrote her part to accommodate. "I did get to sit down a lot, which was a real joy," says Jones. It ultimately adds layers of jeopardy and hope to the story. Clooney revealed to us that, 'The fact that Felicity ended up being pregnant.... gave us something that now feels like we should have done it all along, which is to have this other through line, this future, going through it.'"