Think about your Facebook profile picture. For the most part, these small images are close-ups on faces or group photos with friends. Maybe it's a vacation shot, or a cute picture of your pet. That profile picture is your avatar, a representation of yourself, or a particular aspect of yourself, on the Internet. Avatars, whether on Facebook, Twitter or Tumblr, are our online ambassadors.

As contemporary artists have moved online with the rest of us, avatars have become a platform for art-making and a tool for artists to interact with their audiences. Social media artists, who work with online social networks as a medium, are tweaking their online presence into social sculptures, using profile pages to host discussions and harnessing their Twitter followings into participatory art projects.

Avatars provide a visual brand for this online practice; like the final flourished signature on a canvas painting, avatars tell us instantly who is creating a work of online art, and hint at the artist's style and personality.

Rembrandt might be famous for creating vivid, expressive self-portraits, but for social media artists today, avatars provide a chance to emblazon their self-portrait on every work they make. In this way, avatars are both a signature and a mode of creative expression.

Petra Cortright, a Santa Barbara–based Internet artist who creates quirky and provocative YouTube videos that reference viral Internet culture, usually casts herself in her work with the use of a video recorded via laptop webcam but downplays her presence by remaining silent. Pixel animations of twirling pizza icons and strumming guitars whirl around her in pieces like vveb-cam from 2007, but Cortright stays quiet, showing her face yet veiling her personality. (Similarly, the artist's current Gmail avatar, that little icon that shows up when you email or Gchat someone, is a photo of her with her hand over her eyes.)

When asked if her videos constitute self-portraiture, Cortright says, “The videos I'm most happy with are a good balance of both [self-portrait and not]: They feel sincere and are self-portraits,” but there is another element that takes the pieces beyond simply turning the artist into an online personality.

Cortright's practice of creating weird, semifictional narratives also is visible in her current Facebook avatar, a Photoshopped picture of the artist, which has been digitally painted over into something between an Internet-age pinup and a character concept from the video game Final Fantasy.

It's similar to what Rembrandt or Van Gogh might do — use an avatar, or self-portrait, to represent a specific mood, or memorialize a particular period of life — but pushed into the intensely public, dynamic realm of the Internet.

An Xiao, a Silver Lake–born-and-raised emerging artist at the forefront of social media art, says online avatars “develop into a picture of my creative presence online.”

A ravenous social media user, Xiao maintains profiles on Facebook, Twitter, Tumblr, video-hosting website Vimeo and the Chinese Twitter clone Sina Weibo, among others.

“Avatars reflect on where I am as an artist, where I am in the world, and what I've been working on,” Xiao reflects. On Facebook, you are most likely to encounter the artist in on-the-road snapshots taken during her recent travels in Asia, where she helped curate the Gwangju Design Biennale with Chinese artist Ai Weiwei. But elsewhere in her online presence and in her artistic practice, Xiao modifies her avatars to downplay the physical body as the sole signifier of personal identity.

In “Photoglam,” for instance, she used a glass scrim to turn gallery-opening paparazzi shots into unintelligible blurs, obscuring the identities of any boldfaced names present in a resulting Facebook photo album. Portrait subjects receive un-asked-for, unflattering avatars, identifiable only by Facebook tag.

“The Artist Is Kinda Present,” a performance that riffed on a recent piece by Serbian artist Marina Abramovi in the Museum of Modern Art, saw Xiao wearing dark clothes and black sunglasses, using only Twitter to communicate with visitors sitting directly across from her in a gallery space. Though the conversation took place in close physical proximity, Xiao and her visitors used online avatars to complete the interaction.

“I often obscure faces to focus us on what else is present in digital media,” Xiao notes. “How can we communicate our identity just through text, or just through images that we share of our life without us in them?”

These pieces subvert the traditional idea of an avatar by forcing us to work without the one avatar we are most comfortable with — our own bodies.

Where Xiao and Cortright use avatars to deny or downplay the immediate presence of the self, Brooklyn-based performance and social media artist Man Bartlett sees avatar use as an unmediated, organic outgrowth of identity and personality — he has nothing to hide, and doesn't want to hide anything.

For his May 2011 #140hBerlin performance, during which Bartlett spent 140 hours isolated in a Berlin gallery while tweeting his thoughts about American identity and patriotism to an online audience, he changed his Facebook profile picture to a self-portrait wrapped tightly in an American flag, echoing the Joseph Beuys performance that Bartlett's piece referenced.

During a recent lull between projects, Bartlett changed his photo to a collage of vintage suitcases, reflecting on the instability of travel and the possibilities of an uncertain future.

“I view all of the work I do online as an extension of me,” he says.

On the surface, Bartlett's avatars often serve as signs for his latest project. When he first incorporated avatars into performances, “it was as much marketing as anything else. I wanted people to see it, that this thing was going to happen,” he explains. “But as it has developed, it's become more about my entire being getting taken over by the performance that I'm about to be entering it into.” Changing his avatar “becomes a full integration of the project.”

Chinese artist Cao Fei uses a different kind of online avatar to create her work. In the massive, multiplayer online role-playing game Second Life, Cao's virtual self has aided the creation of an Internet-only Chinese settlement called RMB City.

Artist-created avatars have been popping up even among the nonartist set — new-media organization Rhizome's editor Joanne McNeil uses an animated Twitter avatar made by rising Internet artist Ryder Ripps.

These artists are pushing the boundaries of avatar use on the Internet, but as our own relationships with our online avatars become more complex, we regular online folk could start thinking of avatars with the same expanded view, exploring online self-portraiture's power and potential for creativity. So the next time you're contemplating a profile picture change, just think: What could your avatar do for you?

Man Bartlett's Facebook profile picture shows the artist wrapped up in an American flag for his #140hBerlin performance, during which he shut himself in a Berlin gallery space and tweeted about American identity and patriotism, sharing his thoughts in real time with an online audience.

Petra Cortright's Facebook avatar is a photograph of the artist taken by Franklin Collao for Mexican magazine Caviar Izquierda. The photo was digitally altered by Cortright, heightening her image into a surreal blend of Internet pinup and video-game character.

An Xiao's Facebook avatar shows the artist's mirror-reflected self-portrait in a Beijing bathroom. Also visible is the Chinese character for “woman,” a visual pun: Xiao's first name is the same character with one added stroke that signifies “roof” — here that's the bathroom ceiling.

LA Weekly