No, not compulsory (I prefer to remain anonymous). There are many communities though which like to ask people for photos, social media, etc. to validate they're real people. Which is incredibly ineffective because the fake account creators know "the rules" and are prepared for this.

In WOX, if somebody says they're a professional artist or similar, then we do validate their authenticity - if they're pros then presumably they'd appreciate the additional awareness that Steemit should give them so we contact them through their portfolio website.

Too many have forgotten that one of the benefits of Steemit is anonymity... but this is a consequence of people creating numerous fake accounts to farm the reward pool. Which happens despite the checks 🤷