It may not be obvious to everyone, but Asus put some clear protective plastic on top of the NB and SB heatsinks to protect the finish.

It's hard to detect unless you know it's there and I didn't see any sticker telling users to peel it off.

Leaving it on is hardly beneficial from a cooling standpoint.

Peel it off!! (The NB/SB heatsinks actually have a mirror finish when exposed)