In the Main Scene Creator file there are extra elements such as lights, shadows and background options. If you wish to use these in the pre-made scenes then simply copy them over from the main scene creator file into the pre-made scene.
This is to avoid duplication and to keep file sizes down.
Depending on what colour background and/or what colour designs you have you mat find that the lights are too bright or the shadows are too dark. You can adjust the the fill and opacity sliders of the shadow layers to adjust the strength.