The idea of visual representations of people online is not new: we know them as "avatars" (cf. AvatarAgent). However, just as the wider internet is still on its PenName trip, so it prefers non-real photos: anime characters, photos of pets, and so forth. Conversely, using a RealPhoto--a photo of yourself in reality--can help you mentally AvoidIllusion that your online LifeInText is divorced from your offline identity. That is, it will make you feel that your online presence is merely a reflection of yourself proper, rather than merely some fantasy construction.
Real photos break IdentityProjection?, where people assume that everyone they meet online is the same gender, age, race, as themselves. On the other hand, by visually highlighting gender and race differences, an online community could fall prey to the same stereotypes and prejudices as a meatspace community. Worst case, this could increase conflict. The same applies to names, but to a lesser extent - people can have gender-ambiguous and race-ambiguous names, which may soften the boundaries between UsAndThem. Then again, if one's writing style does not match the expectations for the identity projected onto one, then the "identity KuleshovEffect" might actually increase miscommunication (as it undercuts and scrambles the perceived CommonContext).
As the saying goes as well, a picture is worth a thousand words. Beyond the bare characteristics of a person's visage (age, sex, race, class), the way the photo is shaped also conveys a lot of information about the person. Is the person happy, sad, revealed, obscured? What angle was the photo taken? What background forms the grounding context? What clothes are they wearing? And even the quality of the photo may reveal a lot about the person--RossMayfield's very smart photo is professionally done, distinguishing him head above shoulders from the drab geekiness of the OpenSource community at large.
Even having a digital image of yourself says something about you. Not everyone has access to a digital camera. Of course, more and more people have access to digital cameras (or scanners) as time moves on, but mostly in relatively rich Western countries.
Because photos reveal a lot of information, many people (particularly women and the disabled) obscure their photo in some way to limit what is revealed, often because they have a poor body self-image. Many people airbrush their publish photos using Photoshop or other digital imaging programs. Also, many people choose extreme close ups, extreme angles, bad focus, blurred shots, black&white or strange colours, overexposure, and other photographic tricks to distort the impression the viewer has of the person. Forcing a "mug shot" in your community will raise the BarrierToEntry? against people who find an outlet on the Internet because they are uncomfortable with their physical face-to-face image. (This was abused in AlexAndJoan.)
Thus, insisting on a RealPhoto would be a severe PricklyHedge. Even if you don't insist on one, if that is the visible CommunityExpectation or one of the BehaviouralNorms?, then it may put off certain people. However, the fakability of digital images does soften the impact a little, at least for computer-savvy contributors.
Pure faking is also possible: one can scan a photo it out of a magazine or another website. There are some defences against that, such as a second photo holding a piece of paper saying "Hi Kate!", though they fall to Photoshop. Realtime video and audio is, at least for now, unfakable.
CommunityWiki has innovated here in the wiki space by using photos as optional replacement signatures to follow the style of discussion boards like LiveJournal. CommunityWiki also brings up an interesting problem; since the site is partly for CopyLeft advocacy, its CommunityWiki:CommunityWikiLicense means that your RealPhoto becomes released as CopyLeft as well, allowing it to be mirrored and copied out of your control (cf. SubjectRight). This is a much more onerous example of how OpenContent for OnlineCommunities invades the privacy of its participants. While in most cases this is not a big deal, in the middle of a FlameWar, or when you are being trolled (cf. WhatIsaTroll), you leave your effigy vulnerable to parody and attack. Of course, this is already possible without CopyLeft: a DefensiveCopyright is an imperfect defence.. (cf. CaseOfThePhotoshoppedWife?, [Why you should never put your picture on the Internet])
I don't post images of myself just after crawling out of bed on Sunday morning, my hair a mess, with stubble, glasses, and a slightly glazed expression on my face. Just as there's a wall between my LifeInText and my live-as-lived, so there's the same wall between my life-in-pictures and my life-as-lived. --MartinHarper
A Real Photo does convey a lot of information, which can be both a desirable and undesireable, depending on each situation. A few examples might stimulate our thiking in this regard: