Yesterday we reported that featured snippets can source images from different content sources, so the content they scrape can be on site A, while the image they show in that scraped content can be from site B.
Well, it seems the reason we spotted this, wasn't necessarily because it was new but rather because Google is showing way more images in the featured snippets block than they did before.
I don't know if there is any tool that tracks this change specifically, but anecdotally there does seem to be images coming up in the featured snippets box way more often for me now. In fact, others are saying the same thing, including these two folks:
Here are two random searches I did this morning that immediately broke up an image:
We know Google is constantly tweaking featured snippets and how they work, so this might be just one more step towards that.
Forum discussion at Twitter.