You'll see thumbnail previews when hovering on pagination bullets in the demo. The thumbnail previews are created by the slider's built-in function, thumbnailPreview, with the assistance of the Menucool Tooltip widget.
Please visit http://www.menucool.com/slider/thumbnail-preview for detailed instructions.
This demo has not used the slider's advanced features, hence it does not require slider license. However, a Tooltip license ($20) is required for using the tooltip widget to preview thumbnails.
If you have also included slider's advanced features, slider license is also required.