JennR- good question, and one we are happy to answer. This community site is built on a WordPress platform. One of the advantages of WordPress is that once you create a profile on Gravatar, it automatically applies to any other WordPress based site, without you having to recreate the wheel. We also chose WordPress because of the ease with which we can share content with the community.
Adding a profile pic is purely optional, so while we welcome people doing so, don’t feel like you have to 🙂