Thumbnails are being played in embeded view at top of widget area, but for some reason, clicking on any of them makes the browser scroll to the top of my site as playback begins, making for a strange audio-only experience unless the user knows to scroll back down.
So for now, this means I cannot effectively use this widget in the footer area.
I also noticed that I cannot seem to get thumbnails to not display at all as a work around, leaving just the one recent video. This is because setting thumbnails to 0 makes the widget display 9 thumbnails instead.
See widget issue at the very bottom of my site here: