I wasn’t aware you could display a picture when you log out of WordPress admin. Perhaps it’s something lacking in my education, but I just get the WP logon page. Maybe it has something to do with the fact that you get a 404 if you go to the picture URL you quoted above…
Ouch!
I know it can be frustrating at times when things aren’t working.
But please believe me, I have never had a reason to set permission to ##7
Doing so is an extremely bad idea