Mat Honan, Wired:
It’s a big change to the way Twitter fundamentally works. Previously, when you uploaded a picture to Twitter it was public by default, which was why you couldn’t send them via direct message. Now if you want to send a photo privately, that only you and the recipient can see, you can do that from right within the app.
This will probably be spun as Twitter taking on Snapchat, but that doesn’t seem quite right. Twitter’s photo messages don’t expire like Snapchat’s do. In fact, they can be saved to a device.
But, here’s the thing: Twitter could add one measly little toggle to make the photo expire and, optionally, spin the direct messaging portion off into its own app, and they’d have an instant Snapchat competitor. Just add the “Ew, I didn’t need to see that.”
Also strange: these images don’t follow the standard Twitter image API, meaning that they’re not supported in third-party clients.