The links below are tools used by users when they want to see what a shared post will look like across their platform, but to make the post used to scrape/update the metadata that is used to form the sharing post.
Note: I will use Facebook as the example for this article.
Embedding a post is very easy, most sites allow a user to go to a post or profile and take an embed code from there, which can then be pasted into a website or even publication.
Some website updates their embeds automatically, some need to be updated. Using the tools above you can preview how the post will be shown and keep the embed updated with new information, based on metadata is retrieves.
The scrape again options in the Facebook tool allows Facebook to update/retrieve the new information from the link you provide and then update the post visually from the same screen.