The Perfection (2018) hallucination scene

Granted, ’The Perfection’ is no masterpiece. Personally, I’d say it’s an American attempt at New French Extremity. The hallucination scene starts at minute 34.00 and ends around 43.00.

I don’t suppose many people watched this. I’ve seen it twice and I find the hallucination plot line really bizarre. It’s a common trope that collective hallucinations are impossible; here, not only does Charlotte talk Lizzie into seeing bugs, it’s also framed so that Lizzie is the first one to see the bugs specifically in her arm, facing away from Charlotte. It makes sense plot-wise that Charlotte wanted to trick her into cutting off her hand, but there’s no way she could just talk her into seeing the bugs where there weren’t any. She’s not even a hypnotist.

I know the obvious reason is bad plotting etc, but I’m just wondering if it could he something else. It’s not the most pleasant viewing, either way...