If I take an element (say an Archimate Application Component) and select Appearance > Select an Alternate Image I have a new image for my element. If you want to change the image I can select a different one, if I want to revert to the original I select NONE. I am happy'ish.
If I take an element and select Appearance > Select an Image Asset I can chose from a library of such elements of Type Artefact Stereotype of Image. Great, so far. I can change to a different Image Asset, also great, BUT how to I set the image back to the original element such as the Archimate symbol I started with?
I am sure I am missing something obvious.