User blog comment:Lenopow/Portal 2 Easter Egg - Creepy Message/@comment-190.176.202.166-20160902135929

Rattmann is know for being the only scientist left alive, but also, he could be taken for a superior being, one that we never see, but we know he is there...

This thing like seeing but not with my eyes could refer to the fact that Chell is being controlled by the player, so she in't the one actually seeing.

This could mean that Rattman actually discovered the fact that there was a player behind their lives, like in The Sims.