How can I control which page is used for the Thumbnail?

In the LO Start Center, documents show as thumbnails. But - what controls which page is used for the thumbnail? And - can I, as the author of the document, indicate somehow that a specific page is the one which should be used?

empirically seems to be the first “page”;
with some copy in Start Center : 61174 – (Recent-Document-List) [META] Recent Documents List

with interesting discussions on what could be the cost to implement a choice : 94175 – Please add thumbnail view for Writer

Indeed, it does seem it is currently the first page by default, the question is how can I control that and change it to something else?