Despite having a strong understanding of the application, we may want assistance with certain areas from time to time. PowerPoint offers a tool called Context Help that can help in these situations. If you get stuck in a dialogue, you can use this function to press F1 and PowerPoint will open the help subject for that dialogue. This is really useful because you won't have to waste time looking through all of the assistance subjects to get the one you need.
The context help is based on the currently active window, not the object you've chosen. As your active window is still the main PowerPoint software, if you select an image and hit F1, you will get the generic help panels.
When you press F1 on any other dialogue or window, PowerPoint context help will display the related help subject. The context help will not operate if you continue to work just with the ribbon options on the screen. However, you can press F1 to learn more about the related functionalities of those shapes and objects if you right-click on them and access the related editing dialogues.