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