From what I've seen it isn't going to flow like that. Long and short of it the sketch will be the sketch not much more (if I'm misinterpreting this please correct me). In mobile you will use section buttons for the photos, in those sections it will have photo option and fields for the description (Q, C, etc.) and you can add additional photos with a description. From what I see the reason they are going this way is because of the additional commentary required for every room and the exterior (condition, quality, ceiling heights, etc.), it's not just as simple as dropping a BR photo into the sketch.