One must be careful when photographing non-sedimentary rock art. Some of these monuments have psych-retractable RA. These are that subset of markings which only appear when certain unknown conditions are met*. Even then, it can only be observed by those whom it wishes to be seen by.
This is why the carvings don't like being photographed, photos leave them with no control over who sees what. And one must be careful, because these stones have devised cunning silico-cognisant techinques which produce pulses of causality-rending piezo-electricity. The overall result causes the would-be photographer to be forever unable to convince the rest of the world that the carvings are anything other than his overactive imagination ;)
*A characteristic also shared, though to a lesser extent, by many markings found on sedimentary rock.
