You would not think that the content you find on YouTube, in the description section of a video, is of high quality that Google can use for recommended snippets in the search results. But you would be wrong. Google can and uses YouTube descriptions for recommended clips.
Try this query modifier for [how to replace your lawn mower blade] and you'll see that the recommended snippet that Google is currently using is from a YouTube video:
The video is from Sears and the description is 327 characters and 61 words in total:
This video shows how to replace a blade on a lawn mower. A dull or bent blade tears grass tips instead of mowing, making the lawn look dull. A bent blade causes vibrations that can vibrate and damage the mandrel. Replace the blade with a part that fits your model if it is blunt or bent.
The original search will give you a different video than Sears, but the proposed clip version, with the video, not the text.
This was sent to me by Brian Freiesleben twitter.
Forum discussion on twitter.