I'm making a custom *.saver application, and I would like to add my own thumbnail to show up above the name of screensaver (the ladybug pictures in the left column). How do I do that?

I'm making a custom *.saver application, and I would like to add my own thumbnail to show up above the name of screensaver (the ladybug pictures in the left column). How do I do that?

By examining the default screensavers, I figured out that you need to add two files:
When compiled by Xcode, this is automatically included in the .saver Resources folder as "thumbnail.tiff" with two subfiles.