[mschwaig]

That's an accurate description. I just want to add some info how the install process ifself works so people get a better picture of it.

For the initial installation you actually have to set up the partitions and mounts inside the root filesystem manually similar to what you have to do to install Arch.

Then you run the install command. The install command sets up the system with a default (or customized) configuration and also generates the hardware-configuration.nix file so that it matches the root filesystem you have set up before running the install command.