I am not sure how to obtain the second ending I played it 3 times. The story is quite interesting it does take a bit to peice together the notes and visuals but when you do man is the story deep. I really enjoyed this game.
I got the second ending when I didn't get the knife. By not getting the knife, the flowers won't be there when the body disappears, then finally there won't be any pills in your room. So I think is the knife...