Rarely, if ever, does a horror movie get an emotional response out of me other than horror. I can say that for Midsommar, Mandy, and now this movie, which I’ve heard nothing but great things about. 
It doesn’t over explain who or what has possessed Alice, every performance is very restrained especially for what the movie is about, and nothing is ever over the top like a body flying across the house, rather it gives off a looming presence like someone, yet no one, is there with you. It’s all very realistic in the way it talks about grief and having this need for closure. 
What the movie builds up to is fucking bone chilling, and how appropriate given some of the lines in the movie about mirrors. This movie will perhaps hit very close to home to some people, my condolences if so.