The preview is great to quickly check upon the page you are linking. This way, you can quickly open the to-be-linked page in a new tab and check if it's really the correct page.
This is especially useful when many versions of a certain page exist in your system or different pages with smiliar titles exist.
In the Configure language links overlay, click on the Preview button.
A preview of the page will open in a new tab.
To navigate to the overlay, click on the language button in the header area of your page and click on the Configure button.
On this page
Link to this page: https://seibert.biz/cloud-lama-preview