It seems ImpFighter that the Executor has enough big ass to be a bit on screen :)

First i tryied to be closest the the angle/camera/position with the render of this shot:

You can see it,

and secondly i find something interesting...( maybe wrong)

it seems that Mr vader isnt standing in one position during the falcon pursuit.

The window that he is talking to luke is the no 3 in this^ image

so i assume that when he sees the falcon enters to hyperspace we see him in the center window, so he was walking during this conv.

Fingers crossed :)

-Angel