Looks like a good start and seems to do its job. A suggestion -- you mention "Automatic thumbnail generation" in the feature list but the thumbnails in the dem

Looks like a good start and seems to do its job. A suggestion -- you mention "Automatic thumbnail generation" in the feature list but the thumbnails in the demo have massive file sizes (~80-100KB each at 800px width). Thumbnails should generally be <20KB and <320px width. You could re-use the `createTim()` function you have to generate an additional, proper thumbnail instead of the 800px preview image squashed down via HTML as you do now.