Like, if a web crawler sees a Beehaw post, and then seees Lemmy.ml’s mirrored page of that same post, could it just show up as two different results? Could it work against the SEO in that it gets marked as “duplicate” or “spam” content in some way?
The ideal solution is that the page has a canonical tag, telling search engines what the main URL for the content is: ahrefs.com/blog/canonical-tags/. I don’t know if Lemmy already does this, nor do I know how well canonical tags work cross-domain as I’ve only ever used them for content on the same domain.