Flickr is a website and web service that hosts images and video, and has approximately 92 million registered users.
At this point in time you're can't configure Flickr as a social login provider by using the Identity Cloud Social Login Dashboard. That's because Flickr has updated its social login procedures, and now requires the use of an OAuth app that can't be configured in the Social Login Dashboard. We'll keep you posted on any future Dashboard updates related to Flickr social login.
Note that you can still add Flickr to the Social Login widget. However, when you test the widget your sign-in attempt will immediately fail with the following error: