The first major change is the added tabs for image searches that can have several meanings. Some example searches that would trigger the tabs include [Casablanca], [Apple], [Jaguar] and others. Now Bing has added these tabs at the top to help you refine your query.
In addition, Bing added a preview or live version of the site hosting the image in a frame layer below the image. So if you visit a specific image, you can see the full page it came from. Here is a picture:
You can see a video demo of these new features over here.
Also see our overview article on recent Bing changes announced this week, Bing Releases Huge Set of Upgrades: Maps, Local, Mobile, Travel, Image Search.