Google's featured snippets are now capable of using a different image source from the article content source it used for the answer. For example, a search for [baby boy names] shows the content for the featured snippet from babble.com but uses an image from nameberry.com.
Here is a screen shot:
Aashiya Goyal first notified me of this on Twitter and Glenn Gabe, who tracks these featured snippet features like a hawk, confirmed it was a new thing for Google to source content and images for the same featured snippet box differently.
The image itself does rank well for a search for baby boy names but it is not ranking better than several other images.
One SEO said " I would hate my image to show up with someone else's content."
But this is also how it has worked for years for Top Stories or News box content showing an image from one site but content from another.
Forum discussion at Twitter.
Update: This might not be new as I originally thought... Looking into this.