At about the 11 minute mark the father finds a book under his daughters (liz's) bed called Le Livre Des Espirits or "The Book of Spirits" and although this is a real book by Allan Kardec, the contents have been modified for the film. The first page seen shows a ghastly image of a figure in white with a large open mouth. This image is actually from the 1989 film "Begotten".
U.S. release date coincided with the weekend that the COVID-19 pandemic closed the majority of cinemas in the country.