A mobile device user interface method activates a camera module to support a video chat function and acquires an image of a target object using the camera module. In response to detecting a face in the captured image, the facial image data is analyzed to identify an emotional characteristic of the face by identifying a facial feature and comparing the identified feature with a predetermined feature associated with an emotion. The identified emotional characteristic is compared with a corresponding emotional characteristic of previously acquired facial image data of the target object. In response to the comparison, an emotion indicative image is generated and the generated emotion indicative image is transmitted to a destination terminal used in the video chat.