The chat heads in Messenger design is to display profile pictures of your contacts, not images of their devices. Chat heads are meant to identify and communicate with your contacts easily, and they intend to personalize the experience by displaying your contacts' profile pictures.. This feature is only available on Android devices, as iOS does not support the same technology. For example, on an iPhone, you can add a contact's profile picture to your contacts list, but it will not appear as a chat head in Messenger.