Last year, Microsoft Bing added a new feature for Image Search in which for some product images, Bing will show you where to buy the item. When you issue a query with a shopping intent, referencing items that are usually shopped for ‘visually,’ you will see certain results tagged with shopping cart badges like the above. When you click on the thumbnail and scroll down, you will see image details along with links to pages where the item can be bought, and with related products links if available.
Microsoft today detailed on their official blog about how they built this feature. Read about in detail here.