The YT video they linked is excessively clear about what the issue is. There's no point in explaining it again.
https://www.youtube.com/watch?v=hksVvXONrIo
> Sure, the video you link to is more descriptive, but it's a lot to ask of a visitor to click through and watch a separate video.
alt Hacker News
> Sure, the video you link to is more descriptive, but it's a lot to ask of a visitor to click through and watch a separate video.