she becomes self-aware as a VN heroine and starts talking directly to the player who purposefully chose dialogue options that led to the MC dude having sexy times with another girl on another route despite the fact that you (as the player) already pledged eternal love to her on your previous playthroughs (this bloody scene happens on the second playthrough when you choose the other girl, so the crazy one interprets this as a betrayal on the player's part); she then proceeds to re-program the game itself, which at this point actually crashes to desktop, then restarts and plunges you into her self-made little nightmare world where you spend your days in an an eternal time loop, only given dialgoue options that please her (since she re-wrote the game). There's more to it afterwards but this is the gist of it more or less.