Display Featured Image (if present) above the Content for Posts in Posts page.

functions.php

//* Add new image size for Featured images on Posts page
add_image_size( 'posts-page', 680, 300, true );

add_action( 'genesis_entry_content', 'sk_show_featured_image_posts_page', 9 );
/**
 * Display Featured Image (if present) above the Content for Posts in Posts page.
 *
 * @author Sridhar Katakam
 * @link   http://sridharkatakam.com/
 */
function sk_show_featured_image_posts_page() {
	$image = genesis_get_image( 'format=url&size=posts-page' );

	if ( is_home() && $image ) {
		printf( '<div class="posts-page-image"><a href="%s" rel="bookmark"><img src="%s" alt="%s" /></a></div>', get_permalink(), $image, the_title_attribute( 'echo=0' ) );
	}
}