The secret is to create a suspended ceiling with the Magic Cube tool also leaving small gaps between it and the wall. There, small chandeliers can be inserted/hidden. The light effect appears in Draft or HD snapshot since the direct option to turn the light on does not exist yet. 

Magic Cube is the very last item, white cube, located in the catalogue "Rooms" category. It is a truly magic tool to create various items of your own.

You can also check out that video tutorial. 

We're using the Web version on that video. However, main controllers are the same for all apps, so you won't have any difficulties reproducing these steps on your device.