A method of controlling {HEAD ~ a display apparatus} of a system which includes a mobile device and {TAIL ~ display apparatus}, the method comprising: 
A method of controlling { HEAD ~ a display apparatus } of a system which includes a mobile device and { TAIL ~ display apparatus } , the method comprising :
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH