i hope that really helps attracting more people, then again I've not seen this type of ad yet. Maybe its for certain niches for now?
Seems new to me, it looks nothing like an ad really. More like an amateur decorating something with css borders.
Google says they are testing new types of ads from time to time and see how they perform and then, they might use it generally - as the arrows next to ads - and tell their users about them. Some notes about that here: http://adsense.blogspot.com/2008/09/continuing-to-improve-our-ads.html
It's simply a standard ad made to look like a standard coupon, probably done with the new Google Adwords Display Builder...nothing more.
google put that picture inside the ad block? funny how it's against the adsense tos for publishers to associate 1 picture with 1 advertiser, but google can get away with it.