how you have your preferences set. To get your reply post to appear as the next indented response, just can't happen in this format, afterall, Don's next post to the one you wanted to reply to already occupies the spot you wanted. And since each of those responses had a response (i.e., each new picture posted by Don) your response appears chronologically after all other posts in that thread, which means it appears at the bottom of the thread (until someone else made a post).
Anyway, even if you were to change your preference settings, most others will still see the thread as you now see it, because their preferences are set to viewing the posts that way.
I hope this clarifies, but I'm sorry it changes nothing and can't give you what you want.
Jim