Based on other examples on this blog human head renderings which are often quite lite on details sometimes have what appear to be manufactured 'nostrils' of the nose as seen in this example recovered by Adam Arkfeld at his site. They seem to be an important detail which I have proposed may be adding a 'symbolic breath of life' and animation to the stone.
View of the sculpture from the opposite side. Note the vein of quartz crystals which probably helped inspire the selection of the raw material here by the sculptor. Other examples of sculptures appear to have an unnatural 'lean' to one side, like this one appears leaning back, to the left.