Quirk of Christmas

Mark Evanier posted this on his website, and it deserves being shown all over.  It's a video from Richard Wiseman, whose work I've posted before here.  He's a British college professor of psychology who basically presents magic tricks that aren't really magic tricks at all, but really optical illusions or tricks of perception, which he then explains, all under the brand of Quirkology.  This thought isn't one of those.  It's just a video by some friends of his that he presents.  It's a treat -- it starts quaint and remains quaint but builds wondrously.

https://www.youtube.com/watch?v=dzWYcnE-S7w