Hi Crypticism, welcome to the Forum.
Imagine placing a mirror between the two 2 letter "companies" - you're seeing how they look "reflected".
Regarding the order the posts appear, you can choose whether you want to see the latest ones first or last. Also, when you press "reply to this post". it doesn't appear above that specific post unless nobody else has posted in the meantime. In other words, if 30 people have posted in the time between you reading the post and then replying to it, there will be 30 posts in between the original and your reply. That is why you'll often see people writing "in response to john or whomever at @24", that way everyone knows who and what you are replying to.
I know I've explained that terribly but I promise yuou'll soon get the hang of it:-)