In my system the down arrow means all messages read. Clicking it takes you to the last message in the thread not the first unread since there are no unread.
The right arrow
means there are unread posts and clicking it takes you to the first unread.
The folder changes the read condition of all messages in the thread. If the are any unread messages (right arrow) then clicking the folder marks all messages as read (down arrow appears).
If all messages have been read (down arrow) then clicking the folder marks all messages in the thread as unread (right arrow appears).
Where does your new image come in?
Right now, if I see a down arrow, I have already read the messages in that thread and it will stay down-arrow until someone posts a new message I haven't read. If I see a right arrow I know that there are unread posts in that thread.
Are you looking for a kinda "ignore" thread symbol? Where all new posts are marked as read and the down arrow doesn't change?
Yeah, I can think of a few threads I would like to not spoil my view of the list. I go thru and click the folder to mark them "all read" so my brain skips over the down arrows. It would be good to click it once for automatic ignore.
Look as us RAZD. We are complaining about having to click a button numerous times to constantly ignore a thread. This has got to be some kind of deep sad commentary on human psychology. Percy has us spoiled already but it's just not good enough for our lazy fingers. But that's alright. Coding all this extra stuff helps keep that old delinquent off the streets at night.