During regular WhatsApp voice calls, the app appears to display the default chat wallpaper, according to WABetainfo
WhatsApp is continually updating the app with new updates. The company is now developing a new UX for WhatsApp audio calls, which will include wallpaper, according to WABetainfo.
This functionality was discovered by WABetainfo in the WhatsApp beta for iOS.
During regular WhatsApp voice calls, the app appears to display the default chat wallpaper. Even if you change the wallpaper for a contact, WhatsApp will always display the default one.
This is part of WhatsApp's new voice call UI, which optimises and modernises the user interface.
The new design is pretty attractive, particularly when used in group calls. In terms of calls, WhatsApp has added the ability to join a call after it has begun.
The feature is presently accessible on WhatsApp beta for iOS, but will be coming to WhatsApp beta for Android in the near future. However, there is no word on when this feature will be available globally, as WhatsApp development takes time.