For a long time now, Instagram signature look was a square photo with a filter applied. But users are not happy about this restriction. In fact Instagram reports that about 20% of their uploads have crop lines to allow an upload of a horizontal or a vertical photo.
So starting today, Instagram will allow uploading, embedding and filtering of horizontal and vertical photos.
This is somewhat problematic for Instagram as they are trading away one of their biggest distinctions with ease of use. So the press release kinda juggle between wanting to keep it square and wanting to allow more formats: