nixpkgs/nixos/doc/manual/configuration/profiles/graphical.xml

<section xmlns="http://docbook.org/ns/docbook"
         xmlns:xlink="http://www.w3.org/1999/xlink"
         xmlns:xi="http://www.w3.org/2001/XInclude"
         version="5.0"
         xml:id="sec-profile-graphical">
 <title>Graphical</title>

 <para>
  Defines a NixOS configuration with the Plasma 5 desktop. It's used by the graphical installation CD.
 </para>

 <para>
  It sets <xref linkend="opt-services.xserver.enable"/>, <xref linkend="opt-services.xserver.displayManager.sddm.enable"/>, <xref linkend="opt-services.xserver.desktopManager.plasma5.enable"/> ( <link linkend="opt-services.xserver.desktopManager.plasma5.enableQt4Support"> without Qt4 Support</link>), and <xref linkend="opt-services.xserver.libinput.enable"/> to true. It also includes glxinfo and firefox in the system packages list.
 </para>
</section>