Re-working the Remarkup Box to be smaller, yet provide more information/options/ cleaner UI.
The new images look fantastic, Chad. Really like them.
One additional thought, which is as much an issue for existing comments as adding new ones with the newly proposed UI: could the width be limited, at least of paragraphs if not of images, so lines of text don't become really long and hard to read? I often find this a challenge using Phabricator.
I think that's a more generic issue for Phabricator. Some people want full width, some want fixed with. I prefer fixed-width for reading, which is why all "Document View" apps are fixed width. We may be able to have a selectable option down the road to apply to to (most) other pages.