twitter has always been very confusing with this.

it's basically like a forum chain, where each reply is added over the top of the last, except the chain is upside down after the top level comment. so when you quote someone theit post will be below your post, if someone then quotes that post your new text will be placed below the first quote. at the bottom of the tweet. so it stacks new quotes at the bottom with indentation. so the top is always the newest. the bottom is the second newest, then follow the chain up from there.

it's a terrible system that is unnecessarily complicated and difficult to read.