How to set screensaver thumbnail in Settings panel on Mac?

Question

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?

Answer 1

By examining the default screensavers, I figured out that you need to add two files:

thumbnail.png, 58x90px
thumbnail@2x.png, 116x180px

When compiled by Xcode, this is automatically included in the .saver Resources folder as "thumbnail.tiff" with two subfiles.