I think the grandparent is talking about a better WYGIWYG language, like HTML generally is. You can (and most people, at least on HN, probably do) edit HTML in a buffer.
Edit: changed parent → grandparent
Edit: changed parent → grandparent
> One of the great things about Latex (or raw tex) is that you can simply type it into a buffer.
and pointing out it also applies to HTML.