Thick and thin of eyebrows describe near and far of the objects. Nose describles an abstract course, so its surface is the same as cheek, only brige of nose rised. Also philtrum and the middle joint of upper lip sensibly express the path of action . One abstract object can not form movement. So it is suitable that two eyes represent objects.
Human head expresses basic form of movement.
Two eyes imaginatively represent objects, so the surface of face around eyes naturally represent space. Nose represents the course of the movement. So it represents time. Because movement produces time. Time is a new demesion that is different from the demesions of space, so nose is protruded from face.