Metatags contain additional information about content pages, taxonomy terms, etc.
When a page is shared on social media (Facebook, LinkedIn, Twitter), the social media platform "scrapes" certain metadata fields as a basis for the title, image, description for the preview on the platform.
There are some tools provided by the social media platforms that allow you to see what the platform scrapes.
https://www.linkedin.com/post-inspector/
https://developers.facebook.com/tools/debug/
https://cards-dev.twitter.com/validator
Normally, the Metadata is provided by "tokens" that allow the title of the page to be used for the preview.
One of the metadata fields is for the logo that appears in posts. This is currently set to:
[site:url]/sites/default/files/2020-05/cdisc_logo_social_square_rebrand.png
where [site:url] is the token for the site.
Newsletter Issues rely on a taxonomy for the quarter/year issue and have to be set for each issue.
Example for Q4 2020
https://www.cdisc.org/taxonomy/term/905/edit
Set metatag in Opengraph title field:
CDISC Newsletter - [term:name]
where [term:name] is the token for the issue title.