When viewing a diff page the page banner doesn't render anywhere in the display. See for example:
https://it.wikivoyage.org/w/index.php?title=Utente:Pietro_Di_Fontana&curid=41359&diff=489186&oldid=487345
{F4600611}
As @Andyrom75 later writes:
> As we know diff pages are used to have a preview of the details changed in a page and the saved final result. This is helpful also to patroller to understand if the changes are fine or not.
>
> Currently, the extension do not show the banner in diff pages, and this bug provoke two issues:
> # the shown page is aesthetically different from the saved one, so for example I cannot use a diff page to show which was the graphic effect of an old banner
> # when an user change the banner of a page (like the example above), a patroller cannot validate immediately the action, because he's not able to see if the new file name exist (in this case no banner is shown) or if existing if it's appropriate (maybe has been linked a wrong banner in terms of dimension or content) or last but not the least if it's better than the previous one. In this cases the patroller must open the last saved version to see the banner, than he has to change manually the file name and go in preview mode to see the old one, because the diff do not show the old banner.
Previously diffs were disabled intentionally as part of T110384. Sounds like we want to revisit this discussion.