Hi there John, originally this is a bit of an old post.
This code is included in Shopify, for example the Minimal theme uses this code to deliver a meta property="og:image" to article pages.
With all storefront code the sky is the limit. If it can be done on the web chances are a designer or developer can find a way to program it in.
As for this specific code however it is a theme dependent (and therefore individual designer) addition. Some blogs will show summaries that strip all formatting and not use the image (max readability) while others are mainly product features (max image size) and Shopify blogs can support either of these requirements - it just depends on the specific theme code https://themes.shopify.com/
