Comment 11 for bug 740232

@Paul: currently, unity is loading the image for button using a fixed path for [Amb|Rad]iance themes (see http://bazaar.launchpad.net/~unity-team/unity/trunk/view/1078/src/PanelStyle.cpp#L160).

If using another theme, the fallback buttons are used.

I've took a look on unity-window-decorator, but it just call the same methods on metacity to render the buttons (and I don't find any way to get this as an image instead).

I'll take a look on indicator-appmenu now.