Thank you for your response. If I understand correctly, the scenario for the OG tags solutions would depend on the Facebook post having a URL in it. The image would pull from the URL based on the OG image.
However, what if the post doesn't have a URL? That's the case for the scenario I'm working with. The client makes posts without URLs in them, but would like to attach an image.
I do think it's silly that they want to do this through Kentico when they are already doing it directly on Facebook, but they have their reasons for asking. It seems like it may be a big undertaking for not a lot of value.