You're right, I was slightly mistaken. The screens changes will show, however you'll need to sign in to the live site first. You may see that occassionally when you sign in, there are some screens that generate before you are completely logged in. This is what needs to happen for your portal screens before they will show on the live site. So if you do some customization in the stage site, you'll need to sign out and sign in to the live site before those screen changes show in the portal.
- Adam