It's a reference to an XKCD comic https://xkcd.com/1172/ that pokes fun at users with strong attachments to some software behaviours and/or interfaces.
The interface also allow to comment, post and interact with the original HN platform. Credentials are stored locally and are never sent to any server, you can check the source code here: https://github.com/GabrielePicco/hacker-news-rich.