Social networking sites have really come of age, the now support multiple functionalities designed to improve usability. This is the case for the biggest social networking sites, Facebook and Twitter as they have both seen design changes that may been taken positively or negatively depending on who you ask.
Twitter seems to be pushing ahead from the pack as it has just added GIF support for its PC version as well as its IOS and Android apps. GIFs will not play automatically and you will have to click the play button that will be shown on top of them. This prevents you from downloading large files that you may not need. If you open the tweet by itself, it will start playing the GIF automatically.
Adding this feature puts Twitter ahead of Facebook and will make using Twitter more fun and entertaining. Facebook has refused to add this feature even after some people requested it, the company says that it is worried that GIFs will not look good on its timeline.