My desktop background is a zoomed in picture of my face lmao. I just really love my face and want to see it all the time. I actually have it as a joke because when people are near me when I open my laptop it scares them lmao. My phone background is the same photo I have in my signature.
I have this thing, where I always need my wallpapers to match across all my different devices, otherwise I just feel disorganised and cluttered, so I like to have something consistent so if I need to change it, I can just change it to a different picture of the same sort of thing.
My desktop is just a plain purple background because it's the work computer and my supervisor loves purple. On my phone is a really neat art piece with Nancy's quote in The Craft "We are the weirdos" with blue potions and books and a dagger and stuff, it's really cute but it cuts off some of it and then you can see more of it as you scroll through the app pages.
those are all really gorgeous! I think on my computer at home I have the same fat black cat Halloween background I've had on it for probably 2 years now...