When the project was first announced, Maggie Gyllenhaal was attached to the lead role. Emilia Clarke eventually replaced the actress after the movie was stuck in development.
When Verena puts on Malvina's dress, after she tears her skirt, the dress fits her perfectly. In fact however, there's clearly a substantial height different between the two women. Malvina, is considerably taller and all of the clothes would have needed alterations, if they were to be even wearable by Verena.
Although the film is adapted from the novel of the same name by Silvio Raffo, the film is considered to be a loose supernatural remake of the 1970s psychological thriller, What the Peeper Saw (1972). That movie starred Britt Ekland as a young woman who becomes concerned for her 12 year old stepson (played by Mark Lester), whose mother passed away and who develops abnormal behavior. Voices from The Stone (2017) was released 45 years after What The Peeper Saw (1972).
The distributor rearranged the edit of the movie to sell it more as a horror film rather than a gothic-romance which was originally intended. The director's cut of the movie is still viewable on the director's website.
In 2009, Hideo Nakata was announced as directing this film with a script from Mark Wheaton. George Hickenlooper was being set to replace Nakata when he passed away in 2010. Olga Kurylenko was briefly attached to play Verena but left to act in The Water Diviner (2014) for director/star Russell Crowe.