The Cover image retrieve options don't control the way Audacious displays the cover image in the Popup information window. They control the way Audacious fetches the cover images (that are metadata), and have effect everywhere (on the Info Bar, on the Track Information dialog box, etc.), not only on the Popup information window.
For this reason I think that Cover image retrieve options shouldn't be found under the Popup Information Settings, but as Metadata preferences.
What do you think about it?