Google seems to be testing or launching (or maybe it is a bug) showing a more images section within the featured snippets. I had a couple of reports of people seeing this over the past 24-hours, I personally cannot replicate it.
Here are images from @MordyOberstein and @type_SEO:
In addition to this, people are seeing alternatives to this, like we saw the featured snippet image carousel back in November but also other variations:
