It is already known that WhatsApp is working to bring video calls on the iPhone, but so far we have not seen yet any images related to this feature.
Leaked photos in this article show just a video made by WhatsApp, using a beta version of iOS. Video calling works well in both Wi-Fi in cellular network and will arrive soon on iOS via free update.
The new version of WhatsApp, in addition to video calls, will also bring a new user interface to switch between active chats: instead of having to leave the chat going to be able to choose another from the long history list, with this new version of the various Chat sessions will be selected from a more convenient tabbed interface. This new permit to move so much faster one chat going.
The video call feature was expected, also because it was perhaps the only great lack compared to similar apps. At the moment we do not know when it will be released this update.(Source: Macerkopf [Google Translate])