VisualEditor has some deliberate/non-buggy differences in its display, compared to what readers will see on a saved page, such as the addition of blank lines/slugs to make adding new items at the top of a page. These differences sometimes confuse users.
Add a preview button so that users can see the final version, rather than the slightly different VisualEditor version.
*T49790: VisualEditor: Slugs should be more obvious to the user that they're not "really" blank lines
*T44139: VisualEditor: There is not preview of edit summaries (which are wikitext) - show it in the wikitext diff?
*T39931: VisualEditor: Highlight changes made since save in some way (e.g. with a text-background?) so users can see what changes they have outstanding