where did you find that wallpaper
Here is mine./home/peter1865/Downloads/Screenshot at 2019-05-29 17-13-13.png
Well I did not do that correctly.Have to figure out how to post images.
Open caja (the file manager) and navigate to the screenshot. You appear to have selected /home/peter/Downloads. When composing (or editing) your posts, you can drag the screenshot to your ongoing post and the screenshot should appear to the right of your reply (or post).