You must use Harmony Advanced or Harmony Premium, instead of Control Center, to add elements or drawings to your environment. After you add them in the exposure sheet and save the source, Control Center displays them in the Elements and Drawings panels.
When you select a scene in the Scenes list, all of the elements associated with the scene (background, characters, etc.) appear in the Elements and Drawings lists. Control Center retrieves these components from information you previously entered in the exposure sheet.
You can click the Expand/Collapse buttons to show or hide the Elements and Drawings sections.