I historically have looked for pictures that have a lot of visual depth, like a cityscape or a vista or the ocean or landscape something. It needs to be pleasant to look at and complex but not too busy. I also like there to be a range of emotions that I can feel from it, so that I'm not locked into anything depressing. Generally, the only times I see my wallpaper are when I'm overwhelmed and minimize/close everything, I'm looking for a reset, or on a phonecall and I'm thinking without doing anything else simultaneously.
An added bonus is symmetry, either a vertical line or horizontal, or multiple. Even more bonus is if it's natural AND aligned with the orientation (the picture not just being taken askew of a thing that is symmetrical). So that I can drag the selector with my mouse and make shapes. I know I'm not the only person that does this.
Oh also, brought sunlight and cool colors I find better. Nothing dark and broody or monotone, as those get old super fast. Imperial Boy (an artist) is close, but often either not detailed enough, or too gut wrenchingly melancholy for my sanity, or even not deep enough. Like imagine looking at a picture of a campfire vs being able to stare at an actual campfire. One of those is significantly more pensive.
I'll stick with these for years until I have a need to change, like from a serious life event.
Reading the other comments is wild. Everybody's so interesting and different. The people who are like, "i like this very specific shade of grey" i can't help but let my imagination run. You're either military or like a million of the same exact grey outfits with the same daily routine and the Up! music is playing.
