This is a redirect for google to follow and slows down crawling a bit. Like with post permalinks, the full comment url in de date would be better if possible.
(i just noticed /posts are also full url now which is great!)
I did this for the moment in xf1 -> {xen:link 'canonical:xengallery', $media}#comment-{$comment.comment_id}
Adding 'page={$page}' does not work for comments on pages. I also noticed the canonical url on those pages has no page number so this does not work in the media templates?
Not sure how this is handled in XF2 because there is no media with enough comments to check. And should the canonical version have the page number in it or just the main page of that media because only the comments change when you go next page.