From a mechanical perspective? It uses individual png layers to create a composite character model which can be manipulated as though it were a single image and is very easy to alter.
From a gameplay perspective you can't do too much with it right now (I'm mainly focused on getting the system in place, which will DRAMATICALLY increase my ability to make more events faster) but I'm working on creating a "wardrobe" system for the girls which will allow you to alter their clothes, hair, accessories, etc. :)