Feature: Pull Content Manually.
To use the dashboard, you have to ensure that the checkbox "Enable preview" at the Content Sync Drupal settings is set:
The "Manual Import Dashboard" becomes active as soon as one Pull configuration is set to "Manually".
The preview is generated during the export. You can configure which view mode is used per entity type at the flow configuration.
During the export, Content Sync creates plain HTML which is getting exported and stored within the sync core. This HTML is used to generate the preview. That means if you would like to show images, you will have to use an absolute path for all image and they must be accessible within the importing page.
To show images within the Manual Import Dashboard, we recommend to use the module Image URL Formatter (https://www.drupal.org/project/image_url_formatter). The module allows you to use absolute URLs for the images within the Manual Import Dashboard. By doing so it is possible to create previews of images that are actually available at another Drupal site.