Hi all,
There is no any shortcode for it. To have a blog image medium in your category page it needs code customization. The blog image large is our default blog post.
Go to theme folder(interface-pro)-> inc-> structure-> content-extension.php on line no 125 you will find this code.
$image .= get_the_post_thumbnail( $post->ID, 'featured', array( 'title' => esc_attr( $title_attribute ), 'alt' => esc_attr( $title_attribute ) ) ).'</a>';
replace the above code with this below code
$image .= get_the_post_thumbnail( $post->ID, 'featured-medium', array( 'title' => esc_attr( $title_attribute ), 'alt' => esc_attr( $title_attribute ) ) ).'</a>';
Then your category will be displayed in the blog image medium. Before making any changes in the code first of all create a child theme and then unhook the functions and customize the code to be safe from data loss while updating to our new version.
Thank you!