I don't see a problem. The editing panel in Portfolio is not 100% accurate as it's for editing your pages. At best it's an approximation of what you can expect to see in the actual website when you go to your URL.
I wouldn't worry too much about discrepancies between the editing console and the actual site since you're the only one who has access to your Portfolio editing console.
TIP: Portfolio is a responsive website which means objects align differently on various device widths. Don't expect pixel perfect precision because that's impossible in responsive web design. Resize your browser's window, change your browser's magnification with Ctrl plus, plus, plus or Ctrl minus, minus, minus. Watch what happens to elements on the page.
Hope that helps.
Nancy O'Shea, Product User & Community Expert Alt-Web Design & Publishing ~ Web : Print : Graphics : Media