The video tutorial of this topic can be found here.
The Scene Toolbar is accessible in the Augment Reality and Place view when no 3D models are selected. Tap on the environment outside of the 3D models to have the toolbar come up.
The following are the tools available in your Scene Toolbar:
ADD a 3D model to your scene
CAPTURE your scene and have a photo automatically saved into your device's gallery; you will also have the option to then create a Place.
RESET your scene by replacing and repositioning all your 3D models as you see fit.
FLASHLIGHT will turn on your device's flash (if available) to improve the lighting of the scene