The GIFs are being provided by Twitter partners GIPHY and Riffsy. You should be able to find the perfect GIF to convey the meaning of your tweet or Direct Message from their large library of animated images. Twitter said that over 100 million GIFs were tweeted last year.
The dedicated GIF button will start rolling out today to Twitter users on iOS, Android and on Twitter.com.
Twitter makes it easier to find GIFs for your tweets and Direct Messages
source: Twitter via AndroidCentral