I'll rephrase the GP's question because I'm also curious, and I don't feel your response answered the question. Is there a signal which suggests that "public c

I'll rephrase the GP's question because I'm also curious, and I don't feel your response answered the question. Is there a signal which suggests that "public creativity" equals "good engineer", particularly when the resume already speaks for itself? Or is it purely to compensate, as you suggest, for a possibly poor interview performance? I'm honestly skeptical that such a signal exists (but can be convinced otherwise), except insofar that a person may be invited to give talks _because_ they have demonstrated strong engineering skills or talent -- whereupon, yet again, their resume should speak for itself.