The new feature is able to guess the age of a person in the picture, which is made available by Microsoft; however there is no guarantee for accuracy. In order to understand the feature more clearly, you may want to check it out at the official website, how-old.net.
Before a month, Microsoft at Build 2015 conference officially introduced this how-old.net website. Microsoft created this age guessing website using their Face detection API’s which lets the users to upload a picture which will then be processed by the API to recognize the faces in the picture and predict the age of all faces and finally it shows the user its age guess.
This feature is now available for some of the Microsoft’s Bing users as well. When the user search for the images of people, Bing first displays the list of some relevant images which on clicked opens the specific image. Now if you can notice some highlighted webpage element saying “See age guess” near the top right of the image itself, then it means the feature is available for you. I tried to spot and test this feature in various browsers, but Bing just not showing up any such options to me; however I am able to access how-old.net without any issues. Give Bing Image Search a try (if you like); it might be available in your region.
It is notable that Microsoft is currently improving this feature so there is no assurance for accuracy, but you may still try to have some fun with the age guesser.