While I don't have anything to point to for what this version (Calmira Reborn) specifically looks like, I know that a number of YouTubers have done walkthroughs/reviews of previous iterations of the project. (One such review, of Calmira II 3.3: https://www.youtube.com/watch?v=xMeIwShY434.) I don't expect this new iteration differs much from the previous release; my impression is that this is just a resumption of maintenance and bug-fixing by a different author, so the UX should be the same.

(Also, I can't really blame them for not providing screenshots; it's likely a deliberate choice. If you're using the kind of retro-computing setup that the target audience of this shell uses, you're probably connected to the web through Trumpet WinSock on a 28.8kbps modem — not the ideal environment for loading screenshots! Sure, you could first visit this page on another, faster computer; but you might have to eventually visit the page on your retro-computer to actually download the software onto it. At that time, you'll be very glad that this page doesn't have any screenshots on it!)

I suppose it looks like Windows 95/98, and if you don't already know what that looks like, it's probably not a product you're interested in anyway.

Some here: http://toastytech.com/guis/cal.html