iMore's Serenity Caldwell was amongst a group of journalists invited to NYC last week by Apple for another briefing on HomePod. Her first impressions story is great—I especially enjoyed the fun facts. One such fact is HomePod has an accelorometer so it can detect when it's being moved, and it adjusts its audio output accordingly. Serenity's been killing it lately on Twitter, dropping serious HomePod knowledge on followers who ask questions.
See also: Serenity's piece on what other audio HomePod supports besides Apple Music.