When building output for secondary locales, a locale specific path will be checked for each other file (script, stylesheet, image). For example if you have an image with a file name of images\screenshots\mainscreen.png you can put the translated image for the German locale in this location: images.de-DE\screenshots\mainscreen.png or images.de\screenshots\mainscreen.png (checked after the full locale identifier).

You do not have to replicate the entire set of other files - only those files that exist in the locale specific path will be used during the build and any that are not found will use the main file version.