Emma: "Okay, I'll do bullet points. A) I'm terrified those guys with guns are gonna try and find us because we saw their stupid pot field. And B) I feel so incredibly guilty I couldn't sleep."
Norman: "Guilty? It's not like we were trying to see their pot field..."
Emma: "It's because I was pimping out those dead girls so you would hang out with me..."
Norman: "Ugh, girls."
Emma: "And it was self-serving and I didn't really believe the story until we saw that shed, but then it was like this electric shock. Oh my God, that dead girl is buried there. I could feel it..."
Norman: "Stop, chill, relax. Breathe..."
Emma: "That dead girl is calling us from her grave!"
Instead of rubbing his palms together with trainwreck excitement, like everybody in my house did at this moment, Norman gets very intense on her about this, and finally since she won't chill, demands the journal back from her.
Norman: "It's pornographic and we're at school..."
Emma: "Most text messages are dirtier than this!"
Norman: "But you're, like, obsessed with it."
Emma: "I'm not the one that spends all night staring at it while clicking a rapist's flashlight off and on."
Norman: "So it was in my room... so what? I found it and I didn't throw it away."
She stares, because a second ago they were friends. She doesn't know that's a classic Norma Bates move: State your alibi aloud, even if nobody can hear you and you're okay. You can just shove all those bad feelings way down where they won't ever come back to bite you.
I think what happens is that Norman's feelings about the décolletage of Miss Watson -- who is not Norma's age, true, but is sure as hell not Emma's -- connect up with the journal, in a teenage morass of complications and neural connections that would be grody future kinks in regular life. But because Norman is a crazy, instead/also means that he goes into Smiling Norman mode for a second, possibly blabbing the word burning, before blacking out altogether.
My working theory is that this is a murder we just saw, the Norman cycle of duality and violence and unconsciousness, just... without the actual murder part. We skipped to the blackout, or he kept himself from doing it or he couldn't actually do it. Does that sound right to you?