Only Icon in TOP-LEVEL navigation bar?Browser Info Environment
Is that clear now?
It should be as simple as editing a pages attributes and removing the page name.
So I think it could be a theme option, if the name get's removed with rendering the page.
Maybe with a jQuery script which replaces the first level entries with width space characters.
Because pages without name in the sitemap are also not really funny, right.
Maybe you can think about it and find a solution for it.
But I understand if you have no interest to find a solution over the theme functionality.
It was only a question from my side.