Emojis are great because they enhance modern digital communication by adding emotions and expressions. They also evolve over time as the Unicode Consortium frequently adds new ones. Google delivers the Unicode-ratified set of emojis to Android phones with software updates, so you don’t have to go hunting for them separately. But since these updates take time to reach all Android phones, some of them are left behind with older emojis. Some OEMs also replace the default Android emoji set with their own version, again creating a disparity between what’s available on your phone versus your friend’s phone.

XDA Developers – Feed
https://www.xda-developers.com/change-emoji-on-android/