The Male Gaze.

Marjorie Ferguson

Chocolate box - Half or full-smile, lips together or slightly parted, teeth barely visible, full or three-quarter face to camera. 
Invitational - Emphasis on the eyes, mouth shut or with only a hint of a smile, head to one side or looking back to camera. 
Super-smiler - full face, wide open toothy smile, head thrust forward or chin thrown back, hair often wind-blown. 
Romantic or Sexual - a fourth and more general classification devised to include male and female ‘two-somes’; or the dreamy, heavy-lidded, unsmiling big-heads, or the overtly sensual or sexual.

Trevor Millum

Seductive - Similar to the cool/level look in many respects - the eyes are less wide, perhaps shaded, the expression is less reserved but still self-sufficient and confident; milder versions may include a slight smile. 
Carefree - Nymphlike, active, healthy, gay, vibrant, outdoor girl; long unrestrained outward-flowing hair, more outward-going than the above, often smiling or grinning. 
Practical - Concentrating, engaged on the business in hand, mouth closed, eyes object-directed, sometimes a slight frown; hair often short or tied back. 
Comic - Deliberately ridiculous, exaggerated, acting the fool, pulling faces for the benefit of a real or imaginary audience, sometimes close to a sort of archness. 
Catalogue - A neutral look as of a dummy, artificial, waxlike; features may be in any position, but most likely to be with eyes open wide and a smile, but the look remains vacant and empty; personality has been removed.