It seems Google is testing showing product images in the organic, free search result listings, for certain e-commerce sites.
This was first spotted in a Moz thread for a site that sells ski equipment named evo.com. Here is a picture of the organic listing that shows not just rich snippet data for pricing and stock but also a product image:
I personally cannot reproduce this but some others can. We asked Google for a comment but have not heard back from them about this within 24 hours.
We see these product images often in Google Product Listing Ads but never within the free listings.
We have to assume Google is pulling this data via the schema markup used on the page.
If we hear more from Google on this, we will update this story.
Here is a full size image: