Bingowings said:

It is a bit odd because Leia is clearly emoting at something behind Vader.

Once again one for the fx savvy crowd but maybe if in the corridor behind one of her crew was being dragged off to (or shoved into) a furnace or something to replace the view that's missing.

And a scream would really help punctuate this scene.

I agree. It's a good work, I can honestly believe that there is no droid in that scene. But as Bingowings says, Leia is clearly looking at something else. Maybe you can use another scene from ANH where Leia is looking in the same direction as Vader (and add to that scene the background of her cell) to finish that scene? There's also the noise that the droid makes, maybe you can get the original soundtrack of the movie to fix this?

You are doing a great job, your ideas will make a great ANH edit, keep up the good work. :)