Think
@ieatass69 is onto something. Not for the psychic success since it is looking at the rat, but rather for the perfect success. The perfect success is always shown as looking right at the viewer, or us, it's likely that he realized it's in a fictional world? So there's no point in actually doing anything, and that's why he never moved, as said in p.15.
I don't think this is the case. It's simply always looking forward. It's not that he is always looking at us. It's that we are only given images of him from the front.
I would agree with your theory if we ever see him look at the viewer from any other angle, if he turned his head to look at us, for example.
But no, he's not even looking at anything in that scene, he just had his eyes open. Yume and Hama decided to ignore him, so only see him when they are looking at him, and they only look at him when they enter and leave the room, so from the front. We see him later when the doc is thinking about him, but that's also just a repeated panel from earlier.
Also if that was the case, in classic style of this mangaka, there would be a line like "perhaps he discovered something about the nature of this world?" or "what did he realize to make him decide there's no point in interacting with our world?"