I took the blue header and added the file back in as the demo-banner.jpg file, but now I have a giant banner again. I liked the thin bar which the instructions say is possible, but when I get the thin bar, I always get the alt text on top? I can upload this same blue header image in customization and crop it to the 40 px height but it will never save that way as long as the demo-banner image is in the system. Which is why I deleted the demo-header the first time.
It seems like a bug. The demo file always over-writes whatever I do.