What does community mean when we focus on personal identity online?

Did anyone else see this article in The Atlantic that asks “What is community”? It explores what community comes to mean if we focus on personal identity – in politics, online and in our relationships:

“….Facebook and Tumblr and Twitter and Snapchat and their many fellow services emphasizes identity through a combination of consumption and performance: On Facebook, for example, one’s favorite music and one’s favorite news sites and the memes and jokes one shares suggest, in the aggregate, not just what they like, but who they are.”

I’d argue that things are a bit more nuanced than that – sharing of information in the right context can lead new connections, and that it’s only by revealing something of ourselves that we are able to build meaningful relationships to others. The detrimental effects of focusing on identity seem to come when we hold identity as a rigid, immutable concept, instead of one that it able to change based on new knowledge and experiences.

What do you think? Do we have spaces online where identity can be more fluid? What is the role of the community manager in issues of identity? How would you define community?