It scrolls down to that comment when you use that link. E.g. if you use the link to this post (https://www.simplerockets.com/Forums/View/323167/What-does-the-permalink-option-do-for-comments) it just opens the post, but if you permalink this comment and then use that link (https://www.simplerockets.com/Forums/View/323167/What-does-the-permalink-option-do-for-comments#comment-487240) it scrolls to this comment and marks it with a blue border. You can still use the normal link to get the post itself after permalinking a comment.
It scrolls down to that comment when you use that link. E.g. if you use the link to this post (https://www.simplerockets.com/Forums/View/323167/What-does-the-permalink-option-do-for-comments) it just opens the post, but if you permalink this comment and then use that link (https://www.simplerockets.com/Forums/View/323167/What-does-the-permalink-option-do-for-comments#comment-487240) it scrolls to this comment and marks it with a blue border. You can still use the normal link to get the post itself after permalinking a comment.