I was having a look at a handfull of productions that have rooftop scenes in them. The one that stood out most was Pixars Ratatouille. The thing that got me most about the compositions was the lighting. As its set in Paris and Paris is meant to be the most romantic city the lighting refelcts this. Many scenes on the roof top are at night or sunset, giving it a romantic feel....well i think. So ive renderd my test scene with the same sort of lighting. It is called for in the animation.