This is exactly what was said in that ancient thread: Tree control in labview. So if you add 65536*N to the Item Symbols property of the Listbox and have the "Enable Indentation" option activated, you shift the symbol/glyph and the text N levels to the right.
Could be useful for simple 'parent-child' relationships, if you don't want to use a Tree.
And still it's used in Find Examples / NI Example Finder window: