The source – seroundtable.com
Google is testing a new "Found in video" carousel ("Found in video") carousel in the "Video" tab. The new feature is being tested in mobile search, with a limited number of users seeing it so far.
Apparently, MUM technology is in the works, which should be more widely used in search in the near future.
Now, if Google sees that the indexed videos have content that is relevant or relevant to the query, it can show a carousel with those videos.
For example, here's an example on the query "How to clean white envelopes."