A Image Set is a way of grouping Images (used for Click Bars and Menus), providing an easy method of distributing Images for others to use with their own ISBoxer configuration. In contrast to other types of Sets within ISBoxer (like Key Maps, WoW Macro Sets, etc), an Image Set does not prevent conflicts between names -- the Image names are still global and accessed by a Menu or Click Bar without specifying an Image Set.
When ISBoxer first starts, it will first load its list of all images, and then it will scan the ISBoxer Images folder (InnerSpace\Scripts\ISBoxer Images\) and its immediate sub-folders for any XML files that define an Image Set. For each that it finds, it will import any missing images, ignoring any that are already defined in ISBoxer.
Creating an Image Set for sharing
Distributing your own Image Set is easy with this system. First, organize your images into a single folder under the ISBoxer Images folder (InnerSpace\Scripts\ISBoxer Images\).
Then create a new Image Set within ISBoxer. To do so, you will need to go into a Click Bar or a Menu in the top left pane, to find the Images in the bottom left pane. Right click on "Images (global)" and select "New Image Set". You can then rename your Image Set to something useful (which is probably not literally "New Image Set"). Add your Images to your set by right clicking it and select "New Image"; or if your Image is already added to the list but not within your Image Set, just click and drag your Image into the Set all within the bottom left pane.
After your Image Set is configured within ISBoxer, right click the Image Set and select "Generate XML File". This will help you create a file that defines your Image Set, for you to share. You can either save the XML file to the ISBoxer Images folder, or to your Image Set's sub-folder, but bear in mind that this will be where the XML file should go when installing it as well. For ease of distribution, it is recommended to place it within your sub-folder alongside all of your images; this way, you can just zip up and distribute the sub-folder, which can then be placed in any ISBoxer Images folder for automatic loading when ISBoxer launches.
Note: You may have more than one Image Set XML file in the same folder, defining different Image Sets.
Installing a downloaded Image Set
If the Image Set's creator followed the above instructions, then installing the Image Set is as easy as copying the sub-folder into the ISBoxer Images folder (InnerSpace\Scripts\ISBoxer Images\). If ISBoxer is already running when you install the Image Set, you will need to either manually load the Image Set (explained in the following section), or close and restart ISBoxer to allow it to automatically load.
Manually loading an Image Set XML File
Manually loading an Image Set will import all of the Images from the Image Set, even if the Image was already defined within ISBoxer. Existing Images will be replaced with the new details from the Image Set.
To do so, you will need to go into a Click Bar or a Menu in the top left pane, to find the Images in the bottom left pane. Right click on "Images (global)" and select "Load Image Set XML File", and locate the XML file defining the Image Set.