sensing, by the mobile device at least one of a movement of the captured entity and a change of {HEAD ~ size} of {TAIL ~ the captured entity} according to a movement of the mobile device 
sensing , by the mobile device at least one of a movement of the captured entity and a change of { HEAD ~ size } of { TAIL ~ the captured entity } according to a movement of the mobile device
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH