Looking into the portal
The one time we get a shot through the doorway into the portal (when Malkovich himself is about to enter it), I can't tell what I'm looking at. There's a brief two- or three-second shot of the inside of the portal. It almost looks like the back of Malkovich's head at the end of the portal; however, I'm not sure if that's just part of the "tube". It seems that if you saw Malkovich's head when you looked inside the portal, the first time Craig went into it, he should have had some idea of what was going to happen.
Anyone out there with a Blu-Ray or better vision than me who can confirm or dis-confirm this?