Per https://meta.wikimedia.org/wiki/Special:Permalink/16265861#Page_size_in_Langview, and possibly also add "protection" and "watchers" columns.
This could be useful to measure how well pages are expanded on when imported with the translation tool, or suggest which projects find the subject the most interesting. Unlike Massviews, Langviews will return at most a few hundred pages, so we should be able to get what we want from the prop=info API endpoint without a noticeable effect on performance.