TDE's CDE window decoration style pretty much matches the screenshot. There's also a matching widget style (Motif). I'd guess that the icon set exists Somewhere Out There On The Internet. So you can get this look if you want it badly enough to install a non-default DE that's currently limited to X11.
Looking at that screenshot, even though I've been a very happy KDE user for many years now, I do kinda miss the days when many Xfree86 desktop environments were influenced more by NeXTStep than Windows.
The Motif look, what we are looking at here, is driven by the same UI guidelines that early Windows and OS/2 followed. You will notice a lot of similarity between them.
I saw this in a magazine and it was so cool looking. A few months later I got Linux on CD and never looked back. That 3D Motif/fvwm look was amazing.
Funny enough, my BIOS did not support booting from CD. I remember in DOS, I had to load MSCDEX from a floppy but I have no recollection on how I actually booted and installed Linux from CD.
It should work fine in a virtual machine. Just make sure you provide suitably ancient hardware like IDE storage and old ethernet cards. On something that old, I would only provide a single CPU. To be safe, I would also try installing with a low amount of RAM and then increase it later. Older kernels could not handle multi-processor or RAM above a certain size. I think I might start with 700 MB of RAM to do the install. That might sound like nothing but it probably runs in 8.
It is easy today in our era of resource richness to forget just how meager the hardware was when these distros were new.
A distro that old is going to require some fiddling to get XFree86 ( x11 ) up and running. It should be ok in a desktop VM but I have had problems with older versions of X in Proxmox in case you are using that.
I kind of want to go install this myself now. Or an old version of SLS ( pre-cursor to Slackware ). I ran them both at some point in my Linux journey but it has been a while.
What I really want to do is to make OCI containers from these old distros and try to run them in Distrobox on top of a modern kernel. Has somebody done that already? Really old versions of Red Hat ( not RHEL, Red Hat, < 6 ) would be cool too.
I just noticed that, in the screenshot, it is running in 86box. So, you know for sure it works there and 86box works great on modern machines ( Windows, Mac, and Linux ).