Generate an 8-10 second video brief centered on a live-commerce product demo presenter. Build it with three concrete beats: open by establishing the adult presenter, product area, and visual promise; move into the main product gesture or spoken demo beat with a clear camera path; end on a stable hero frame that can work for a landing page preview, product showcase, or social cutdown. Anchor the sequence on natural facial motion, clean lip-sync or reaction timing, stable framing, and audience-appropriate delivery. Specify pacing, lens feel, camera distance, lighting, motion blur, and continuity rules so the output stays readable. Keep subjects, props, locations, text, and logo areas editable. Avoid real brand names, celebrity references, fixed IP, readable signage that cannot be changed, unsafe action, sudden teleport cuts, inconsistent scale, warped anatomy, and unrelated extra scenes.