In portrait drawing the arabesque is the entire positive shape, the gestalt (whole) of the head. The arabesque incorporates the proportion (height/width ratio), the shape and the symmetry. Thus within the arabesque is communicated the likeness and emotion of the portrait drawing.
But herein lay a significant drawing problem: looking and seeing.
When we look at a face a complex schematic comes into play. Whereas we all see the same face our mind’s eye (the limbic receptors) compresses the visual image into a symbol or paradigm. These paradigms (models of experience) are patterns that our limbic receptors have classified as symbols.