What do you mean, exactly? I don’t believe the Editor is really intended for making those sorts of changes - that’s what the Designer is for. If you’re using the Editor you have no access to the page div structure etc, so I can’t really see how that would work.
Editor is for writing blog posts. Blog posts need photos.
The interface makes it hard to add photos to posts.
They do let you add photos, but there is this awkward interaction where you have to make a return, then hover your mouse on the left hand side for a while until a plus button appears. Not intuitive, and it doesn’t work consistently. Another user discovered that the only way to get this some what functioning is to delete your cache every time you want to add a photo.