Despite the square limitations, Instagram users had previously uploaded non-squares anyway. A reported 20 percent of photos didn’t adhere to the square and were filled out with borders above or beside.
Fast Company explained how the new feature works:
Instagram being Instagram, it’s tried to implement the new capability in a way that doesn’t introduce unnecessary complexity. When you peruse photos and videos in the app’s gallery, they’re cropped into squares by default. But tapping a new icon lets you preserve their original orientation, be it landscape or portrait. That’s about it.
Instagram product manager Ashley Yuki told Fast Company, “When we started taking on this project, there was some skepticism. One in every five moments I’m seeing basically feels like it’s not natively supported by our platform, which is not great.”