Question: How are images inside a post handled?

Using the latest WordPress and pluging; just got the paid version installed yesterday.

Everything is configured and seems to be running well.

My question: If I have a post that includes an image (not a featured image — I mean just inside the post), how will that be handled if I post it to my Facebook page or LinkedIn feed and use the {content} tag?

I see that when I set a featured image, that image appears properly. But sometimes my posts include an image or two in the post itself. Will those not appear unless I also make them “featured images”?

Thanks for the help/insight. I’m trying to figure how I can share different kinds of post.