A mobile system may comprise a three-dimensional (3D) image sensor on a first surface of the mobile system configured to perform a first sensing to detect proximity of a subject and a second sensing to recognize a gesture of the subject by acquiring distance information for the subject; and/or a display device on the first surface of the mobile system to display results of the first sensing and the second sensing. A mobile system may comprise a light source unit; a plurality of depth pixels; and/or a plurality of color pixels. The light source unit, the plurality of depth pixels, or the plurality of color pixels may be activated based on an operation mode of the mobile system.