37 new emojis added including melting face, heart hands, etc.

With the release of iOS 15.4, 37 new emojis were also added. 7 face emojis and several objects have been added. Among the many changes, there are some that are impressive. The hand-to-hand smiley emoji was expressionless to express 'surprise', but now it is impressive that it has changed to 'laugh' like emojis provided by Google and Microsoft, including a smiley expression.

Source: https://blog.emojipedia.org/ios-15-4-emoji-changelog/