Stickers are growing in popularity on the web, with Facebook leading the way in Messenger and in status updates and comments. Other chat apps, including WeChat and LINE, also support the feature, which has seemingly led to Twitter wanting to join the party too.
Twitter's implementation of stickers differs a little to others, mainly because instead of adding a sticker to a tweet (which would feel a bit weird), they're added to pictures. Stickers can be resized, rotated, and moved around until you're happy with their placement. Furthermore, these stickers can be clicked on, just like a hashtag, to see ways other users are using the same sticker.
— Twitter (@Twitter) June 27, 2016
Support for stickers is rolling out to the Android and iOS apps over the next few weeks. It doesn't look like an app update will be required, but just in case, here's the latest Twitter app update over at APK Mirror.