I made a post on this thread:
http://texags.com/forums/12/topics/2583283/replies/41804377
I quoted a picture posted by another poster and added a picture of my own, using the appropriate bracketed IMG tags. The pic I quoted appears as an image error icon, and the pic I posted does not appear at all. When I quoted my entire post as a new post to see what would happen, the comment I added appeared within the quoted portion, despite not being composed in the quoted portion.