You can reupload a file using the widget and it will replace your original file with the new file. If you want to just clear it, you could probably create a microflow that creates a new object (that you are using to store the image), use the copy attributes java action, and then delete the original object.
Hope this helps!
Thanks for the suggestion.
Unfortunately deleting the image object will trigger cascade delete on children objects, so that would be problematic.
Having said so, I may need to:
This may become an acceptable workaround, but I am surprised, that there are no actions to clear it.
Thanks for the suggestion,
Looks like you can do this with a bit of Java, based on a forum post from a few years ago: