Images near Google Ad units are an effective way to increase the click through rate without violating any of the Adsense policies.
What's so appealing about this new style is that the image is an ad itself. So publishers get best of both the world's without doing any labor.
About the screenshot: This is 120x600 Adsense Format with Image Ads turned On. The image file dimensions are 90px x 110px with a size of 2.34 kb. The file is hosted on the Google Ads Server - googlesyndication.com