btremFrom context, it seems reasonably certain that "my h-card didn't show up in the webmention" means he commented on a post, but the comment lacked an author.
artlungthat's good. That brings to my mind the fact we have additional ways to call in an image these days, <picture> and <source> notably that may make more work for a mf parser. Keeping it simple seems best where possible.
btremYeah, but I'm saying that you don't need to apply aria to prevent screenreaders from reading an element with display: none because, AFAIK, screenreaders don't read such elements.