A device determines whether a speed mode between the device and an external device is a first speed mode or a second speed mode, communicates with the external device at first speed if the speed mode is the first speed mode, and communicates with the external device at second speed slower than the first speed if the speed mode is the second speed mode. The device enables transfer of image data and displays the image data being transferred to the external device, if the speed mode is the first speed mode. The device disables the transfer of the image data and stops displaying the image data, if the speed mode is the second speed mode.