I remember paying attention to the technical aspects for the scene. Roger's eye pops and then there needed to be a stagger, a subtle back and forth, back and forth, animated on 1s (like the rest of the movie). I thought the pencil test looked pretty good until Dick Williams pointed out that during the stagger the eye still has to follow Bob Hoskins' movements.
I adjusted the animation, but there still seemed to be something awkward with the way Roger was placed into the live action scene. A lot was going on with the pillow and the blanket. They seemed to have a life of their own.
I tried a couple more times to make Roger fit into the bed, but it didn't look perfect.
Guess what, ILM placed a shadow over the screen's lower right corner to take the edge off this combination issue. It sure helped a great deal.
In the following scene Roger exits the bed before jumping back on it. It turned out that Bob Hoskins' eye line was too high before the rabbit arrived in his upward position. The solution was to stretch out Roger's arm, so Hoskins looked at the hand, and a few frames later the head.
There were times when we all had to be creative in order to make the animation/live action combo believable.