I get a section “analyze” with a list page that correctly lists the page “introduction”. The page “introduction” contains a <img src="image.png"> which is displayed in the browser all right.
The German version of the pages (de) is placed in the public/de subfolder as intended. The list page lists the German version “introduction” correctly as well. However, the image is not found, because Hugo emits it into public/analyze/introduction/ once and not into public/de/analyze/introduction/, where it would be expected by the German version of the page, which also contains <img src="image.png">.
The obvious, but in my opinion undesirable solution would be to hard-code the path to the image in the German version of the page: <img src="/analyze/introduction/image.png">. This is prone to cause broken links should I ever decide to rename the section or page name. I’d like to avoid this risk and keep my pages DRY.
introduction is now a leaf bundle, as opposed to having the content files in the parent branch bundle (?) as in my first attempt. Admittedly I had a hard time wrapping my head around Page Bundles. Hugo now emits image.png twice, once into public/analyze/ and once into public/de/analyze. Using rdfind, I can replace the duplicates with symbolic links to save space on the server:
rdfind -makesymlinks true public/ public/de/
It requires the web server (Apache) to be configured with the FollowSymLinks option.
Concerning the Page Resources, I have also started using them now, although I do not see what benefit they offer as long as the image is not to be processed in the asset pipeline. Referencing the image by filename (<img src="image.png">) just works fine.
However, in fact I do now generate image thumbnails with the asset pipeline, and those thumbs are being emitted twice as well, once for each language.