WhatsApp is reportedly working on a new messaging feature called message reactions. Message reaction is exactly what you think it is: the ability to react to a text message using an emoji. While it was always possible to react to a message by quoting it and then sending emoji in reply, message reactions will make the experience much more streamlined for WhatsApp users.
Apps like Instagram, Twitter, Signal, Slack, and Facebook Messenger have long offered message reactions, so again, WhatsApp is playing catch-up with the competition here.
The evidence of message reactions in WhatsApp was first spotted by WABetainfo, which believes that the feature will be available in a future update for beta testers. Similar to Instagram DM, WhatsApp users should be able to add emoji expressions to individual messages once this feature rolls out to users.