By default Editor/ed_icons folder (in downloaded zip file) contains emoticons subfolder only. This subfolder contains image files. If you want to add your own icons for inserting to HTML Editor's content, you should create new subfolder(s) in Editor/ed_icons folder. Place your icons into the subfolder(s). Every such subfolder name appears in TABs of Insert Icon popup window.

Example.



Next window will be opened on toolbar's Insert Icon button click.