In the admin console if you select the reset button on a category property it just resets your selection. Which doesn't add functionality as you can become the same by just not pushing the save button.
We configured the system to use the icons from SRM. Once selected an category icon this icon will take precedence. This currently can not be undone. You can only select another icon.
The reset button should revert to the use of the SRM icons if this option is active.