When I did use a mobile phone when I was still working,I had a photo of our beloved BrownDog as the background! He lost a battle with cancer and both my son and I were devastated, Like you,I felt a certain sadness when I saw it,but I also had such happy memories of the hilarious antics he would get up to with the other dogs!! It was the best picture I ever put on that phone! So,do not remove your picture,Finy,unless you really feel you wish to do so. I did get great comfort from seeing my funny friend all the time,even just in a photo!! Aaaah! Brown Dog,,Bless your Heart! we still love and miss you.
No, I'd never thought of putting a photo 'there' I'll be visiting my daughter in Melbourne in a couple of weeks, so I'll ask her to load up a photo of our granddaughters, or a photo of tulips! A friend also has a dog, but she has 'wallpaper' of a vase with a bunch of blue iris's I gave her a couple of years ago.
I've just had a look at my phone, for this question. It has the picture it came with, but I couldn't even have told you what that was, if I hadn't just had a look at it then, as it's next to me on the bed! It's a grey picture, with a bit of a snowy mountain on the right side, that slopes down to the left side. The sky is covered with the 'Milky Way' I guess 1 could call it.