Your "..\Templates\Images" folder, located beneath your Fast-Help installation folder, contains your expandable paragraph images. By default these are called:-
You can change the contents of these images or add your own. If you do not have these images you can download them from:-
and unzip them into your "..\Templates\Images" folder.
How do I use my own Images?
Highlight some text and select "Insert | Expandable Paragraph". Use the ellipsis buttons to select your Visible and Hidden images. These will automatically be copied to your "..\Templates\Images" folder. You can select [Cancel] if you do not want to insert an expandable paragraph at this time, your image changes will still be saved.