What this is
- A strict logged-out control check for YouTube embed playback using a widely-available control video id dQw4w9WgXcQ.

Observed
- The embed URL renders: "Video player configuration error" with "Error 153".
- Two screenshots were captured ~18s apart attempting playback; the files are bit-identical, consistent with no playback progress.

Environment
- Browser: Mozilla Firefox (Private Browsing)
- Signed out
- Capture: full desktop OS-level PNG screenshots