in which transfer thumbnail images 85 a in the upright state are rotated clockwise or counter clockwise by 180 u00b0 i e in which the images 85 a are turned upside down the wording u201c reception set up in progress u201d is displayed on the receive side display screen 7 b transfer thumbnail images 85 a that have been turned upside down are stacked a transfer thumbnail image 86 a is in the upright state by rotating the upright transfer thumbnail image 86 a clockwise or counter clockwise by 180 u00b0 a transfer thumbnail image 87 a that has been turned upside down is displayed on the transmit side display screen 7 a fig1 c illustrates the situation when main image data is sent and received displayed on the transmit side display screen 7 a is an image in which transfer thumbnail images 85 a that have been turned upside down move one frame at a time toward the input output portion 8 a displayed on the receive side display screen 7 b is an image in which transfer thumbnail images 85 b in the upright state move laterally away from the input output portion 8 b one frame at a time fig1 d illustrates an example of.