Configure display of blog cards in this section. In your control panel, go to Storefront > My Themes, and click the blue "Customize" button to launch Theme Editor. In the left hand column of the Theme Editor, click the panel labelled 'Blog'.
Show summary in cards
Enabling this option will display a summary, i.e. the first few lines of the post in blog cards.
Show author in cards
If a name is entered in the Author field on blog entries, enabling this option will display it in blog cards.
Blog cards are what's displayed on the home page (if blog is set to display on the home page), and on the blog page (i.e. https://www.yourstore.com/blog).