The page names an SVG icon and that is what a current browser uses. One that
does not read SVG icons asks only for /favicon.ico, got a 404, and showed a
blank tab — the defect the SVG was meant to close, still open for that reader.
The ICO is the same mark, byte-for-byte what hanzo.ai serves, and it hangs off
the brand row like everything else: a host with no row still answers 404, which
is the right answer for an operator with no mark.