Extensions in Droid Explorer can already handle specific file types. The shell console and sqlite explorer are good examples of that. When you right click on a file that is handled by an extension you will see it as an option.
Extensions can now implement DroidExplorer.Core.Plugins.IFileTypeIconHandler. This will allow an extension to define how the icons for the specified file are rendered. Here you will see the new PictureExtension. It shows a small thumbnail of the picture as the icon of the file.
These icons will be cached in the users Droid Explorer Data/Assets directory so they can be loaded from the cache to load faster.