Please disregard if this is unrelated, however I’m currently running 3.7.10, and yesterday I changed my new uddashbard from -content to -pages.
As I stared to declare my pages, I noticed my page the page name was at the top left too (I am in the middle of converting a site from UD 2 to PSU 3 and learning PSU at the same time). I finished yesterday, still trying to work out how to remove that text.
You need to put it in a published folder to host it and then use that URL. If you publish at /assets/ then the URL for the image would be /assets/logo.png.