Lauren Ridloff had difficulty in reacting in scenes where she is required to interact with a digital character or in action scenes due to her deafness. She credited Angelina Jolie who helped her by using a laser pointer pen to guide her in the direction she would be required to look at.
Lauren Ridloff's father gave the main cast lessons in American Sign Language so that their usage of the language to communicate with Makkari was all the more genuine.
The Celestials were first mentioned and briefly seen in Guardians of the Galaxy (2014) when the Collector explained the origin of the universe and the Infinity Stones.
(at around 1h 9 mins) Kingo and Sprite discuss Sir J.M. Barrie's Peter Pan. In the comics, Sprite is mentioned as having met Barrie and directly inspired his Peter Pan character.
(at around 1h 10 mins) Dane is mentioned to have an estranged uncle. In the comics, said uncle is Nathan Garrett, a supervillain and Dane's predecessor as the Black Knight.