Sorry Kammer didn't mean to sound arrogant, there is so much to the stones and all the other prehistory stuff that it isn't just one theory, it's more like an endless chain of theories, part from you, part from me, parts from others, crossing all kind of topics, subjects, object etc, ... I've been familiar with the stones for quite some time now and can get a reasonale understanding to the stuff. One learns to look at them in a different way, people who 'see' easiest are usually carpenters or artisticly talented people.

This one at The Cove, is so clear it nearly comes of the stone, note the headdress patterns, adjust your eye to it, I haven't scaled or measured it but there is no doubt that it has the gridding incorporated.
http://www.themodernantiquarian.com/post/40952

Identifying comes with alot of technique, like closer up images that show the different texture; depth/smooth/dry/chipped/stonecrust/direction of modification.
Follow these colourdifferences.
Sequence;
1 standing point
2 second silhouette
3 shades
4 textures
All in combination of the boxgrid.

Like if one changes ones thoughts from a crude lump of stone to a sophisticated work of representation one is halfway there.