At what point in the movie...

I really like your post, it's an interesting thought to gather after watching this effing movie. For the record, I can't get it out of my head, it's so visually striking and just impressed me beyond belief with the editing, direction, and of course the performances.... but when it comes to the narrative I get all iffy because I don't know if it's portraying mentally ill people from start-to-finish or if they "snap" at some point -- like for example when you feel it's when Sam Neill is in the rocking chair.

I thought they were both insane, unstable individuals in the "pre-divorce" discussion at the restaurant. The two of them are positioned apart from each other in such a weird way -- they're just SO DRAMATIC! Like that scene where Sam goes tearing through the restaurant and throwing every single chair in his path around -- it looked like he seriously wanted to hurt Isabelle and then she's just making it worse by kind of letting him chase her as she screams her head off... I would've just tried to exit the building and call for help. But that's the realistic part of me -- sometimes I wonder if this film has a setting in reality at all. The restaurant scene shows a couple peripheral people standing (I think) who are watching what's going on, but it's pretty much depicting these people in empty places to where it looks like they are the only people who exist.

I knew for certain they were disturbed people after one of the frenetic argument scenes in their gross messy house -- and she's like screaming in the bedroom and she slaps him -- and the way he just transforms his mood into this weird sexual undertone by saying "Do it again" and how she just slowly begins to smile with her bloody teeth. At that point I was convinced it wasn't just about the female/Isabelle being psychotic -- it's definitely about BOTH of them as a pair just losing their sh*t.

Honestly I kind of give up on the narrative aspect. I watch it repeatedly and I can never figure stuff out, so I love to sink into the masterpiece cinematography and just Isabelle acting like a scary ass creepy woman from hell - the camera captures both her insanity and her delicious beauty at the same time. I get chills at the part she MANIACALLY STARES directly into the camera giving like the effing evil eye UGH it's so SCARY lol. She seriously looks like a mentally ill person -- sometimes the camera captures stuff that just looks way beyond acting to me. I understand why Isabelle called it "emotional pornography" because it's like a movie that depicts the evil in humanity so candidly that it's terrifying. I sum up the movie as just evil. I think it's about evil possessing her, and then she radiates it to Sam Neill's character after it "happens" when she says "it's difficult" or something in the kitchen scene. I dunno.

This couple definitely had to have met each other in a psychiatric ward. They probably even got married in some morbid way. Two extremely morbid people.
(Sorry I did digress quite a bit, I don't want anyone taking my wannabe-analysis to heart, so if you have a different interpretation, that's fine, I'm just sharing my thoughts. People on these boards are pretty rude and hateful.)

It took me to the scene when she starts putting the clothes in the refrigerator while saying she has to do the wash.
As far as he was concerned I never thought he was gone. He just seemed to be desperate to have her back at any cost. Which in itself may be construed as over the edge anyway.