The screen was found in a beta version of the app by wabetainfo. It gives instructions for checking a code with your main phone. Currently there does n’t appear to be an actual code to scan.
A screen found in a previous beta showed that devices could be getting the ability to sync recent messages, even though they’re end-to-end encrypted. The screen instructs users on how to use WhatsApp on another device.
The feature is available on both iOS and Android. It’s unclear if the feature will also be available on iOS if and when it launches.