I think we only modified our design about 4 or 5 times. We tried to see if we can see anything from by the reflection of mirrors and we modified it when we can't see anything. We actually don't really know what to do and we nearly quit on the half way. We listened to one another's opinions and they we modified it.
I would suggest not to put too much effort on whether you fold the papers wider or narrower because basically you will see the same reflection from the mirror. Use cardboard wisely because it helped a lot.