Instagram is working on a full screen stories display creating a Connect 4-style display grid of tappable Stories.
Instagram has confirmed the test to TechCrunch, noting that it's currently being tested with a small number of users.
With more people using Stories, at some point, it seems likely that Instagram will look to switch the main focus of the app from the traditional post feed to a Stories feed, with the 'classic' Insta stream shifted another tab. That, of course, would be a significant change, but as parent company Facebook has repeatedly noted, Stories are on track to overtake the news feed as the primary surface for social media engagement, if they haven't already.