Well, that's annoying: the complete path and folder info included on the very bottom of the Image Preview window does not always update when switching between duplicate images.
Another bug: If the Image Preview window is minimized and restored, all the buttons and path information disappear altogether.
Also: Path and folder information is not included elsewhere in the Image Preview window, either, but it should be—ideally, with the rest of the detailed EXIF/file info displayed to the right of the main preview photo. Y'know: where people are already looking.