You can now upload both portrait and landscape photos without having to fuss or dread over whether or not your photo will fit the exact dimensions (usually 610 pixels wide by 610 pixels high, although Instagram will take pics up to 640 pixels by 640 pixels).
Fans of the new feature love the extra cinematic look.
To upload a larger than usual size photo, simply upload the photo as normal and before publishing it,click the little icon in lower left to toggle between portrait/landscape mode and regular mode.