Just Edit is the newer interface for editing content within Omni that creates a shadowbox
around your content, so you can see how it will look while you are adding content.
This can be set as your default editing style in your user settings (click on your
name in the top right) or you can activate it by holding the
shift key when you click on a green edit button. Since it is using your final published site
styling, any changes you make can be seen immediately when you edit content.