I think the scene where the killer mimics the sound of the MCs heartbeat let’s us know t...

I think the scene where the killer mimics the sound of the MCs heartbeat let’s us know that he knows MC isn’t blind. He took that picture purposely because he knows the bf is narcissistic and would post it, having the MC see and be terrified. He also looked up at the apartment of the bf when he was cheating, what’re the odds he’d just happen to look at that specific window?
Also, he mentions “the game” and “log on”, and I think this refers to how the MC is trying to convince the killer he is blind and the killer wants to see how far he will go.