I think they are barriers to keep people out. I think everyone has barriers like that, ya know what I mean? I think in one of the previous mangas, it showed Ino's father going through a hallway, with banners on each side of the hallway. I think those were put in place by Pain, but not all the big white ones where the brain is... I also made a post about the black antennas... remember that this is NOT one of Pain's bodies, this is just a regular ninja in Pain's village. I think the hallway barriers are a two way street, to keep outside people out, but also to prevent the interrogated guy from seeing a true reality... remember he thought that it never rained in his village, and that it rained off schedule when he entered Jiraiyas frog tavern barrier.
