viz.

From The Guardian:

Commentator (old style). Ideal pose requires baleful gaze at reader as if he/she personally responsible for politico-moral decay. Examples: Peter Hitchens, Sin Simon, any Daily Mail curmudgeon. Pro: Suggests man so nauseated by state of nation he is barely able to stop himself vomiting. Con: Role of male Cassandra hard to sustain—risk of disillusioning readers if seen giggling tipsily in local pub.

Commentator (new style). Prettification reaches the comment zone, with political penseurs portrayed with a nascent, ambiguous smile. Examples: Simon Heffer, Simon Jenkins, Andrew Rawnsley. Pro: Embodying nation’s agony under socialism/ Thatcherism/Blairism full-time no longer required. Con: Followers from grumpy days likely to ask, “What's he got to smirk about? Country's going to the dogs!”

You can find the whole list here. (Unfortunately, there are no example photos.)

Here’s a nice description of the growing importance of the headshot in social media applications from the Slate article where I found the link.

Remember for a moment how much attention people used to lavish on the perfect quote for their e-mail signature. Now that self-conscious energy is applied to a photo. There's nothing inherently bad about the rise of Web head shots. They just turn what was once a space for burgeoning Cyrano de Begeracs into a space for burgeoning Brad Pitts. Read the stark conclusion of a 2000 meta-analysis of beauty studies that tried, in a careful way, to discover whether beauty really was in the eye of the beholder:

The effects of facial attractiveness are robust and pandemic, extending beyond initial impressions of strangers to actual interactions with those whom people know and observe. Contrary to the conventional wisdom, there is strong agreement both within and across cultures about who is and who is not attractive. Furthermore, attractiveness is a significant advantage for both children and adults in almost every domain of judgement, treatment, and behavior we examined.

In other words, this analysis confirms the elegant Montaigne observation that it quotes: “[Beauty] holds the first place in human relations; it presents itself before the rest, seduces and prepossesses our judgement with great authority and wondrous impression.”