This is a teaser. It's to invest you in the rest of the video, will you wait to see it unfold to get to the teaser. This used to be a mainstay of the nightly news, back when people used to watch television. They put the most sensational thing in the first 30 seconds of the broadcast, and then in the last few minutes they'd go over the sensational thing.

An international conspiracy to poison your children, but first let's look at this week's weather.....

Think of it as the original clickbait, where instead of clicking you had to wait for the story to unfold.

On the short video platforms, like TikTok, Instagram, it's the videos that say watch until the end! The same b*******

To grab people's attention, or because YouTube started autoplaying videos in the mobile app when you scroll past them so they need something to make you click at the start. If you use SponsorBlock you can skip recaps like that

Traditional TV shows did it sometimes. Just a way to hook the viewer I think.

Does anyone know why this trend started?

Reality shows

https://www.youtube.com/watch?v=7MFtl2XXnUc

As someone who browses almost exclusively 9n my phone, I appreciate having a moment to pause it, flip my phone sideways, and adjust the resolution because YouTube always defaults to crappy.

Sometimes it might just be to make the video longer (filler.) I hate seeing a 10 minute video that could have been 4 minutes or explained in a short paragraph (written text.)