From https://blog.twitter.com/2013/improvements-to-login-verification-photos-and-more :

“Today’s Twitter for iOS and Android updates let you enroll in login verification and approve login requests directly from your mobile app. Now, in addition to the SMS-based login verification that we released in May, you can use login verification without relying on text messages.”…….

“As you type your query, the search menu with suggestions will include social context, so you can see how you’re connected to other users. We just introduced this last week on twitter.com.

We’re also adding a new photo gallery in search. Before, when photos were returned in search results, you could swipe through thumbnails and select photos to view full-screen. Now, you can select a new “View more photos” option that will lead you to a photo gallery of all the photos related to that search.”

Read rest of blog post at https://blog.twitter.com/2013/improvements-to-login-verification-photos-and-more