Why aren't my posts marked as replies?

I have noticed that some posts in this forum are marked as replies to other posts. Here's one example. If you look at the top right corner of the post there is a little reply arrow and a picture of the avatar of the person who is being replied to.

Also, when I write a post that I intend to be a reply to someone else, I can see the person's avatar at the top of the editor pop-up (and I can click the reply icon to choose how to respond, which is a neat feature).

But the actual post is unmarked. For all I can tell it looks the same as a reply to the topic.

Doubly confusing, if I edit this post again I can still see the avatar at the top, so Discourse is clearly keeping track of the post I replied to, just... choosing not to display it. Why not?

I find this very annoying and have been wondering about it for months.

I think it's because your reply is right after the message you reply to.

Hmm, I guess I can see why that would be useful? But it still displays the same as a reply to the topic, which seems wrong to me.

I usually don't like to @ the person I reply to because Discourse will notify them anyway. But for a third party reading the thread it can be confusing not to know whether a post was a reply to the latest post or to the topic. I remember one recent case where I made this mistake, although I can't find it at the moment.

Thanks. I'll see if I can recontextualize this as a feature instead of a :beetle:

I believe that, when you reply to a specific post (including the immediately-prior post) the poster gets notified of your reply. In addition, if that was not the poster who created the thread, the thread creator also gets notified.

When the post is to the poster of the immediately prior post in the thread, no avatar is shown because the identity of the poster to whom you are replying is apparent from the sequential nature of the thread. Thus it is only when you are NOT replying to the prior poster, but to some other poster, that the avatar is shown.

Except when you are replying to the topic / original post, because replies to the topic are displayed exactly the same as replies to the most recent post.

So using the blue Reply button at the end of the thread is a reply to the original post, whereas using the font-colored Reply button at the end of the line directly under any post is a reply to that specific post. Although that is different semantics from what I stated, the result is the same unless someone else posts while the reply is being finalized, before it is posted: no avatar is displayed unless the reply is to an earlier post by a poster other than either the prior poster or the creator of the thread. Thanks for the clarification.