The images are blocked in the help pages all versions of Joomla, because the wiki verifies someone being human at the moment (after being down a lot). Only things served via the proxy help-server are visible, but the images are served directly. So that must be repaired, but is not Joomla 6 specific.

Joomla 6 uses the Joomla 5 help pages. The few things that were specific for Joomla 6 (like the number field) were added to those help pages with an annotation since what version they are available. But we have to adjust some titles to say: Help with Joomla! 5 and 6.

Thank @HLeithner for fixing the broken images

Changed title to Joomla! 5 and 6. Adjusted some other texts. Will adjust other texts if necessary. Best we can do now until we serve the Help pages from another source than the wiki.

Still don't know why the anchors are not working, but if I'm correct that is only on this "Start here" page, and not Joomla 6 specific (doesn't work either in 5.3). Don't see a difference with the anchors on that same page in the wiki, where it is working.

Markup on top of license visible is also not Joomla 6 specific. Is in this case because the license of Joomla 4 help page was used. (and that HTML is not stripped out). To change it the article should be copied to the Help5.x namespace (not ideal that we have the same license text double, but better than that markup) and change the place where we refer to that Help4.x page. Will do a.s.a.p.

When the license problem is fixed I guess I can close this

Solved the rendering of the Help -> Joomla Help -> License page. It was the only page that had no translation and in some way or another that triggered that wrong rendering. Of course the license itself must not be translated, but I added a translatable paragraph on top of the text of the GPL license and then it works. (If you don't see the correctly rendered page some caching might still be involved).

Still no clue why the anchors don't work on the "Start Here"page. They work if you see the page via the proxy, but not embedded in the CMS backend.

Issue can be closed. Thanks for reporting it.