Sluggo said:
Interesting idea. How would it fit with R2 and 3PO's dialogue?

Threepio is a translator droid so he understands it just as he understands R2 and the Falcon.

R2 reacts to the light change (has the scan noticed his hidden cargo?).

It makes the scene more menacing and mysterious from the door side but remains in character from the droids side.

Remember we get enough evidence of the whole of the conversation from just Threepio or the scene as it currently stands wouldn't make any sense.

The thing that doesn't work is the comedy coming from the doorside of the conversation which removes alot of the sense of danger from the scene and is an obvious nod to similar scene in "The Wizard Of Oz".