Newbie question: Can I use Exiftool to get Facebook preview for a PDF?

[skeptic23]

I have a PDF I want to post on Facebook.

I want Facebook to pick up a preview image instead of just a blank with the file name.

I know how I can use Exiftool to add the document title.

Can I add a link to an image file so that Facebook will "see" and use it?

The attached image shows what Facebook shows now, and below it what I want to see.

[StarGeek]

I want Facebook to pick up a preview image instead of just a blank with the file name.

Do you have a source that shows this is even possible?  From what I can tell from a quick google search, the only way such a thing can happen is through hosting the pdf on your own site and using some scripting to trick fb into thinking the PDF is an image when it first checks the link. 

[skeptic23]

Haha, no, no source. Thus "newbie" question. I thought there might be some way to put a link to an image file in the metadata somewhere. FB doesn't get the previews for news articles and videos from the page or video content themselves. Somewhere in the metadata there's a link to image files.

[StarGeek]

FB doesn't get the previews for news articles and videos from the page or video content themselves.

Actually, in some cases, it does.  Look up Open Graph image meta tags.  In the web page source, they'll look something like
<meta property="og:image" content="https://example.com/wp-content/uploads/2018/02/default_image.png" />