Google has started to show AMP results in their image search results. If you go to Google Image Search on your mobile device, do a query and click on the image results. You can swipe through the image results, and some may show an AMP logo. When you click on the title of the image, it takes you to the AMP version of the page.
Here is a screen shot of this working on my iPhone:
Here is a screen shot from @willdropphoto showing it works from Android as well: