Yes, that is a square video below. Click on the video to see Snoopy and the Peanuts Gang enjoying a night under the stars (ala Vincent Van Gogh’s famous painting “Starry Night”.)
To answer the question: Do Square Videos Work on Pinterest?
The answer, right now, is that Pinterest does not support a square video. Alas. I certainly hope that they support all sizes and shapes of videos very soon.
By the way, YouTube does accept the square video format but YT makes it fit within their standard shape, so the video ends up having two strips of black on either side of the video.
Here is the YouTube video with the width and height adjusted to eliminate the black strips on the side of the video:
Facebook does support square videos. Check out this Facebook post embed:
Here’s a graphic of the opening frame of the video: