{TAIL ~ an external output unit} configured to output a signal of contents including {HEAD ~ an image} to said second wearable display, and 
{ TAIL ~ an external output unit } configured to output a signal of contents including { HEAD ~ an image } to said second wearable display , and
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH