A technique of directly and simply operating image data stored in an external storage device using a camera is provided. To accomplish this, an image processing device connectable to a network, comprises a connection unit configured to connect to an imaging device, an acquisition unit configured to acquire image data captured by the imaging device from an external device on the network, in accordance with a user operation on the imaging device, and a display control unit configured to display the image data acquired by the acquisition unit and image data stored in the imaging device in accordance with a display unit of the imaging device.