Thus, when {HEAD ~ a viewer} views {TAIL ~ the exterior} of the lamp generally in elevation, the cover selectively displays different designs to the viewer depending on the illumination state of the device 
Thus , when { HEAD ~ a viewer } views { TAIL ~ the exterior } of the lamp generally in elevation , the cover selectively displays different designs to the viewer depending on the illumination state of the device
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH