I started writing out a review, but I went ahead and just made the edits instead, since it was all fairly objective. Changes include:

• Calling it "COSMIC Greeter" rather than "COSMIC-greeter".
• Correcting the heading levels for the image labels.
• Minor grammatical tweaks like adding Oxford commas in list sentences.
• Making the syntax within the image descriptions a little more consistent, and moving some additional info from the image descriptions into the normal text.

It's my opinion that the initial setup wizard is straightforward enough to be self-documenting, but I don't have a problem with adding this section to the article.

I think it'd be a good idea to add a few instructions on how to update your system either via COSMIC Store or the Terminal at the end since updating your fresh installed OS usually is one of the first things you'll do after doing a new install of your OS.

Aside from that, I think it looks overall good.

Nice addition to show the initial setup of the system after the install. All of the images look good and I see no odd formatting while running this in NPM.