It is a non-linear map which have many paths to take and reach the end. The point is, that you play a map one time and you are happy. Then you have a little break in Portal, because there aren't any new released maps for some time. But the answer is here: play the Deja-Vu again, but choose a different path with different puzzles. You can choose freely the way that is going to lead you to the end. Thats it!
random
Cool !
I <3 love <3 this mapping style so much:D .
I actually found a way to get the CC in this room; used a portal on the roof above it and then placed alot of crap to climb back up with my cubey friend. Then I took him as far as I could. :3