The scene of the main character’s death is what they’ll see and then once the main character regresses, they also regress with no memory of the events from the day they regressed from. The world in the book flows in real time to the tower. Which is why when the main character spoke to the tower supreme beings he requested to be brought back as the butler and not as the player. Because if he is the butler, he can be spend any amount of time prior to the time required of him to save the world of the book because he is only a character and not the actual player. If he was made to come back as the player, he would have only 10 exact days to plan everything from the start to finish. And considering the complexity of this romance world it would be extremely difficult to do alone. That’s also why he requested his lover to retain memories of him, which also allowed him to skip of the extra formalities needed to earn his lovers trust again. Hope this helps (◕ᴥ◕)
I'm honestly just wondering how all that regressing is being showed to the people outside the book (since they're being broadcasted)