When Roy reached out to Red Guy near the end, i think that It was to stop him from messing with the controls. He saw how the machine tortured and rended his son's brain to mush, and wanted Red Guy to end it once and for all. The control that the machine had over the three of them, along with Roy's manipulation of it. So Red Guy unplugs the machine, ending it's influence over him and his friends, and everything starts over, without the machine being the middleman between what they see and hear. So when the notepad returns at the end, it's genuinely going to teach them how to be creative, without saying what is "creative" and what is not. The machine no longer has any power, Roy is gone.