It fits the aesthetic of projects like RADAR or other series that simulate death or psychological distress through grainy, distorted video files.

The "petra.mov" file appears to be part of a niche or Analog Horror ARG (Alternate Reality Game). Based on current digital traces, here is the report on its context and significance: 📂 File Analysis: petra.mov

Depending on the specific community you found this in, it likely refers to one of the following:

A psychological drama directed by Jaime Rosales. While not "horror" in the traditional sense, it deals with dark themes of family secrets and ruthless characters, which often triggers "creepypasta" or mysterious edits online.