I would refer to that as the About page, and it's specific to the desktop being used. Every desktop has it, but it looks different if using Unity, GNOME, Xfce, LXQt, MATE, KDE Plasma, etc...
The program (thus command) also varies on the desktop you're asking about; as my system is a multi-desktop install; I have multiple installed (one for each desktop, ie. one for Xfce, LXQt, MATE, GNOME... and the command used controls which opens)
xfce4-about is the Xfce ABOUT app & thus command used to display the ABOUT details when using Xfce/Xubuntu.
lxqt-about to view the LXQt ABOUT app & details which apply to the desktop I'm currently logged in with & using. (I logged in with a Lubuntu session today, thus am using LXQt currently)
You can use whatever ABOUT apps you have installed, but a Xubuntu install comes with
xfce4-about only by default as it's using the libraries/toolkits & details of the Xfce session that is running on a Xubuntu install.
You didn't provide an actual release you're asking about (and the focal page you showed was from early 2020 or late 2019 prior to 20.04 being released), but to view the GNOME details you use
BUT that will require it to be installed; which it is not on a default Xubuntu system (it is on my own bloated system as I have four desktops installed)