He opened it in a forensic video tool. The ghost track showed a classroom, but not the one from the film. It was a real classroom, dusty, with a green chalkboard and a calendar from March 1999. A young girl with messy braids sat in the last row, flinching every few seconds—involuntary movements, just like the protagonist’s hichki (hiccup). But these weren't acting. They were real.
This indicates the source was a high-quality digital stream, ensuring better color accuracy and sound clarity compared to older "Cam" or "DVDScr" versions.