WhatsApp tweaked a new feature of four reactions preview in chats via Wabetainfo blogpost. The latest WhatsApp Android 2.22.16.6 update brings a reaction preview within the chats list. The new WhatsApp beta for Android version increased the number of reactions that show up within chat bubbles.
As shown in the screenshot, in the previous update, up to three reactions were visible within a chat bubble, but with the latest update, users can see four reactions.
Reportedly, there is a notification issue, which will be fixed by WhatsApp soon. The ability to view up to four reactions within chat bubbles is available to some beta users and will roll out to more users in coming days.