I haven't found any SSR photos with the sofa bed open. But you can see in the photos at DVCNews.com that there is a night stand between the two.
http://dvcnews.com/index.php/resorts/saratoga-springs/maps-a-photos If you are worried about your DS falling out of the sofa bed, you can request bed rails. I've read that they work well on the pull out couches in the
DVC villas.
Hopefully someone else will have photos of the couch open and the bed.