If the guider is attached to an element near the top (and presumably bottom, left, right, etc) of the page, it is positioned outside of bounds.
See this screenshot: F29544
Code:
tour.step( { name: 'close', titlemsg: 'multimediaviewer-tour-close-title', descriptionmsg: 'multimediaviewer-tour-close-description', attachTo: '.mw-mmv-close', position: 'right', buttons: [ { action: 'end' } ] } );
'rightTop' is doesn't work as the arrow/caret seems to have some sort of minimum distance, and the arrow/caret ends up pointing at the fullscreen button, which is inappropriate.