I also found it confusing. I was wondering if it was this person's preferred pronoun but their Twitter [0] lists "she" as of "January 2022" and all the testimonials use "she" too [1].

[0]: https://twitter.com/EverfreeArtemis

[1}: https://artemis.sh/

The article is written to be read back in Gollum's voice

Nah, the author is royalty and is referring to the use of the laptop by themselves and by their sovereign station.

It's possible the author has multiple personalities, it's a good thing that they are running a multi-user operating system.

I mean, I suppose it's a reasonable pronoun for someone to use if they wish to be referred to as "they" ...

"They" is almost exclusively singular in those circumstances, regardless of its etymology. Similar to how "you" derives from the old English second person plural pronoun, but is in virtually all variants of modern English acceptable for the second person singular.

By definition it does. I'm not sure what weird literary device the author is going for here.

No, it's just a pronoun flex. Spend as many cycles on that as you think it deserves.