Whatever grabs the mood. At least when I USED to have phone wallpapers, that was my motivation. Can be a band or a figure, or logo or photo taken.
What you are asking is someone to hand over their personal photo collection, which people know can be used more than ever for catfishing and deepfake?
Better doing a conversion of some kind, for example send me 3 photos you have of yourself, and I'll create and an animated gif/sticker doing exactly what you want in cute cartoon format. Although people can really do that with the right ai tool anyway.
You might find that there is a market for noobs that don't know the tools for things you can do. (your skillset) Just depends. Like every idea, follow it through to completion, so you can market, and decide if its worthwhile to go further, and be something of potential.