That sounds like a yarn to me.

Nah, he likes something to grab hold of.... though I heard he's just learned it's a better idea to stick their back leg in his gum boots.

In reality...none.  They are all a selection of images which mostly suit as wallpapers [backgrounds to a desktop], not images specific to an OS/Computer logon screen.

When logons included skin components for the Users panel etc. [pre Vista] they were 'genuine' skins, not a single wall image applied behind whatever default OS logon panel/details.

They are now  [in Vista and 7] frustratingly 'simple' one-image backgrounds.

An idea 'might' be to create a background that has graphics/details pointing to the user logon 'bits' applied by the OS.  The issue there is they'd be specific to however many users were listed/shown.

In 'simplistic' terms a Logon 'could' have some dopey message saying "You are logging on to Win7 64" - whatever.

What Snowman's saying is that the post-XP logons really are nothing more than a wallpaper [if that] ...