Instagram is introducing a way to share photos in portrait and landscape orientations, but only in private messages. You'll still have to work your Instagram magic to share photos the old fashioned way, but now at least when you're messaging your friends you can send memes back and forth without having to worry about the size of the image.
That's not the only new feature for Instagram Direct, however. You can also send links to your friends in direct messages, including things for websites and other images, as well as phone numbers and addresses.
These are small changes, but they're crucial to Instagram building up its messaging component to truly compete with WhatsApp, Facebook Messenger, and others. Ironically, Facebook owns most of these, but at least you can't complain about feature parity.
source: Instagram
