A head-mounted display, HMD, system comprising a first body and a second body, the first body comprises: a display unit configured to display visual information; a first angle sensing unit configured to sense a first angle of rotating the first body with respect to a horizontal position; a first communication unit configured to transmit/receive data; and a processor configured to control the display unit, the first angle sensing unit, and the first communication unit; and the second body comprises: a camera unit; a second communication unit configured to transmit/receive data; and a second angle sensing unit configured to sense a second angle of rotating the second body with respect to the horizontal position, wherein the first communication unit and the second communication unit transmit/receive a signal to/from the processor, and transmit/receive a signal to/from the camera unit, wherein the second body is mountable to and detachable from the first body, characterized in that the camera unit senses an image while the second body is detached from the first body, wherein each of the first and second angles of rotation is an angle rotated clockwise or counterclockwise with respect to the horizontal position, wherein when the second body gets detached from the first body, the processor is further configured to: acquire the first angle of rotation and the second angle of rotation; display an image preview corresponding to an image created by performing a first rotation compensation on the sensed image based on the second angle of rotation; detect a first capturing signal, wherein the first capturing signal includes at least one of a touch input to the first body or the second body and an audio input to the first body or the second body, wherein at least one of the first and second bodies comprises an input sensing unit; and capture the sensed image and store an image created by performing a second rotation compensation on the captured image based on the first angle of rotation and the second angle of rotation, wherein the second rotation compensation represents compensation through rotating the captured image by an amount of a sum of the first angle of rotation and the second angle of rotation. a display unit configured to display visual information; a first angle sensing unit configured to sense a first angle of rotating the first body with respect to a horizontal position; a first communication unit configured to transmit/receive data; and a processor configured to control the display unit, the first angle sensing unit, and the first communication unit; and a camera unit; a second communication unit configured to transmit/receive data; and a second angle sensing unit configured to sense a second angle of rotating the second body with respect to the horizontal position, acquire the first angle of rotation and the second angle of rotation; display an image preview corresponding to an image created by performing a first rotation compensation on the sensed image based on the second angle of rotation; detect a first capturing signal, wherein the first capturing signal includes at least one of a touch input to the first body or the second body and an audio input to the first body or the second body, wherein at least one of the first and second bodies comprises an input sensing unit; and capture the sensed image and store an image created by performing a second rotation compensation on the captured image based on the first angle of rotation and the second angle of rotation, wherein the second rotation compensation represents compensation through rotating the captured image by an amount of a sum of the first angle of rotation and the second angle of rotation.