The pattern of the large cells identifies {HEAD ~ orientation} while the exact shape of {TAIL ~ the large cell} will be an indicator of skew 
The pattern of the large cells identifies { HEAD ~ orientation } while the exact shape of { TAIL ~ the large cell } will be an indicator of skew
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH