GIFs will **w appear in your timeline with a play button, like other video content. You can upload GIFs through the gallery button under the text box in the same way you upload a photo
Twitter users can't share video on Twitter unless it's shared through Vine, so GIFs are the first video-type content available to regular users (**n-advertisers). Users could previously share GIFs to the service through Twitpic, but the new GIF support feature seems to have eliminated Twitpic's full functionality with Twitter.com Read more...