The video is stuck in an `<img>` tag so you need to wait for it to load. On a slow connection it might just not show for a while. Though the video is only 1MB so should load in if you wait.

I have >400MiB/s on this machine and had already spent several minutes reading through the explanation/instructions before scrolling back to the top; it just never loads for me. I had to manually open the link in another tab, for whatever reason.