Three weeks ago WhatsApp started implementing a shortcut in group chats in WhatsApp beta for Android which was intended to make it easier to make group calls.
At the time the shortcut was non-functional, but with WhatsApp beta 2.18.370 the feature is now available to testers.
Previously to make a group call on WhatsApp for Android users have to call one person in the group and add the other members.
With the new icon, a user can easily call all the members in a group chat, either by voice or video.
The same feature has also been added to the iOS beta earlier. Sometime after testing commences the feature should roll out to the general public.
To get access to this feature you can join the WhatsApp beta program via the Google Play Store here.