WhatsApp's latest beta update (v.2.17.285) for Android adds a couple of new features to the app including storage control, push name tags for unknown contacts, and most notably a feature that will allow users to switch between voice and video calls. A new camera button at the bottom right corner of the call screen will allow users to seamlessly switch between voice and video with a single tap.
Additionally, a minor change introduced in the beta version of the app allows users to zoom into profile pictures of their contacts. However, since the new features are just part of the beta build it is not necessary that they will make it to the stable release.
Source: Beebom