This name belongs to Zenji and exists only to test one measurement. It is served through a content delivery network, and the server behind it also answers anyone who asks it directly by its own address. A site set up like that can be reached without passing through the network that is meant to stand in front of it, and Zenji's probe is built to notice exactly this situation.
The probe first fetches this page the ordinary way, through the delivery network, and keeps the answer as its reference. It then connects straight to the address of the server behind the network, presents this name in the TLS handshake and in the Host header, asks for the same path with the same browser user agent, and does not follow redirects. When the direct answer is the same page as the reference, the name is recorded as reachable at its origin, with both answers kept as the proof.
The two bodies are compared after markup that the delivery network adds on its own has been removed and after whitespace has been collapsed. Either the normalised bodies are byte for byte equal, or they share the same title, the same stylesheets, scripts and form targets, and nearly all of their visible text. Headers are never compared, because the network rewrites them by design. Short pages, default server pages, parking pages and error pages are never treated as proof, which is why this page carries several paragraphs of ordinary text.
Before such a measurement is shown to anyone, it has to be seen to find a real case and to stay silent on cases that only look similar. Many probes against names that are not reachable this way have already returned no match. This name is the opposite case, set up on purpose, so that the probe can be shown to find what it is meant to find. Nothing here is secret, nothing here takes input, and the page changes only when the test changes.
Questions about this name go to the owner of the zenji.io domain.