Saturday afternoon I was searching for some ideas and all of a sudden every image I clicked on displayed a new interface as per this image:
The lefthandside image is as per the "usual" interface however you will note that they are displaying "Try these too".
When one of those images were clicked they appeared on the lefthandside. I haven't been able to repeat this as yet but at the time I had been searching through a lot of images, maybe two hours or so, and I wonder if they've built in a "Let's try and help this person out type of feature"?
Next I suppose will be AdWords as some of us have already mentioned.