What are the scary details in Invisible Guests?

At first, the man and Laura were in a remote hotel, and they could feel that Laura was in a bad state. Previously, the man said that Laura had a short hair cut after the incident, echoing the explanation that she had anxiety and kept losing her hair. At the same time, the interested audience confirmed that Laura was not a femme fatale as the man said, and judged that the man was lying. At the same time, when reviewing the beginning of the film, the man drove Laura, and Laura sat in the co-pilot and took some scenic photos with the camera. The film gave these photos a freeze-frame close-up. In the second half of the film, the protagonist receives an anonymous letter with threatening photos and recordings. Smart viewers will find that this photo is Laura's original landscape photo.