Over the years, emoji has managed to occupy a considerable portion of our text based communication. Those with devices capable of entering and viewing emoji often use them on social networking sites such as Twitter. However, even today, several major platforms and browsers don’t natively support emoji, which leads to their users not seeing the text the way they should be.
To solve this problem to quite an extent, Twitter has now started identifying emoji in tweets and replacing them with their own custom emoji on the web that can be viewed regardless of the platform or the browser. For example, currently both Windows (7 and 8) and OS X can display emoji in their default browser (IE and Safari, respectively) but not in other browsers such as Chrome or Firefox. But with this new feature, if your browser does not natively support emoji, you will see Twitter’s custom emoji instead.
Twitter is using images instead of actual emoji, which are text based characters. Because of this, any browser can display them regardless of the platform. This is only for Twitter web, however, so if you’re on a mobile platform that does not support emoji (such as pre-Jelly Bean Android) then you will continue to see empty squares in tweets. Also, the Twitter emoji don’t work if you embed the tweet.