Show Thumbnail Background Color: Selecting this
will display the thumbnails using the background color you set using
the Thumbnail Background Color Option.
Show Thumbnail Highlight Color: Selecting this will
place a large border around the thumbnail you click on in the
thumbnail sheet indicating that you have it selected.
Show Thumbnail Font Background Color: Selecting
this will display the names of the files using the background color
you set using the Thumbnail Font Background Color Option.
Include Sub Directories: Selecting this will
include all image files in sub directories of the currently selected
directory to be included in the thumbnail sheet.