After removing the .DS_Store file from the images/headers folder, the Header admin panel is displaying the header image thumbnails perfectly!
And yes, it is important to remove .DS_Store files before migrating the site to live server, or they will hitch a free ride and end up on the server.
So Mac users, pay attention. To remove .DS_Store from any folder, open Terminal and navigate to the folder.
cd path/folder/ (example: cd Documents/ followed by cd Websites/ followed by successive folders all the way to the child theme’s ‘images/headers’ folder)
ls -al (displays all files, including . and .. and .DS_Store)
find ./ -name “.DS_Store” -depth -exec rm {} \; (removes .DS_Store from this directory and all subdirectories)
Now the code from David Cox over at Digital Raindrops is working beautifully – allows for locating header images in the child theme’s folder, where they will not be vulnerable to overwrite – AND – also generates the display dynamically – no need to manually add to array every image you create; simply create header images and thumbnails and save to the folder designated in the code. 🙂