That means that anything that doesn't know what "NAS" is (meaning, anything outside of my house) can't see any images.
I see that in the config, my WordPress Address (URL) field shows "http://nas/wordpress", and it's grayed out.
The Site Address (URL) is editable and shows the proper URL.
I suspect that is what causes Wordpress to insert media with a link to http://nas instead.
I'm loath to go in and edit the wp_config.php file willy-nilly, but I understand that my issue should be resolved if I insert these two lines in it;
Is that correct, or should I look elsewhere for a setting to tell my Wordpress install to not use "NAS" for the name?
Also, when I get that name changed, what will I need to go to get all my posts updated to not point to http://NAS but to point to http://mydomain.com instead?