Instagram has always wanted to be more than a place to filter your photos. That's why your Instagram app has a news stream. That's why you have the ability to like and comment on other users' photos. Instagram is its own social network - not just a service to make your posts on other social networks more interesting.
That's why it shouldn't really surprise anyone that Instagram just disabled its Twitter cards integration, the result of which is non-optimal, poorly cropped photos appearing in users' Twitter streams.
Instagram CEO Kevin Systrom immediately addressed the Twitter snub as he took the stage at the LeWeb conference today. According to The Verge, he apologized for the shift being "confusing" to users, but made no apologies for doing what he thinks is best for Instagram.
Systrom said that pulling the integration was "the correct thing for our business to do at this time." But he also said that Instagram and Twitter are peachy and that Instagram will always be integrated with Twitter.
So you'll always be able to easily cross-post your Instagram photos to Twitter, but they're just going to look crappy in that format.
Of course, what Systrom wants is for Instagram users to, well, use Instagram. Not just the mobile app, mind you, but Instagram's brand new web profiles that they launched early last month. With the new web profiles, users can browse any user's profile and see their entire photo collection. Users can also like and comment on photos straight from the web. When you think about it, Instagram is simply a "news feed" away from being just as much a web entity as they are a mobile entity.
And not playing nice with Twitter cards is one way to encourage people that everything awesome about Instagram can be found within the walls of Instagram.