Google launched highlighting of text within featured snippets some time ago, after a ton of testing. We saw it also in people also ask and now we are seeing it in the “things to know” section.

Here is a screenshot showing how the “Things to know” section on the right side, when expanded, can highlight portions of the text, just like people also ask highlights and featured snippet highlights:

This was spotted by Khushal Bherwani the other day and he posted this on Twitter:

I mean, this makes sense, they are all part of the featured snippet family.

Also knowledge panels:

Also, notice the favicons in the “things to know”?

Forum discussion at Twitter.