This documentation is still in progress. We are working hard to update all our screenshots to the new Magnolia 6 style. Please bear with us.
The Preview app allows you to test personalized content. You can impersonate a visitor to verify that the correct page variant is served. The impersonated visitor can be a persona or a mix of local traits. The Preview app looks just like the preview in the Pages app but it has a sidebar for selecting the persona and traits.