add_action( 'genesis_entry_header', 'sk_image', 9 );
/**
* Outputs image linking to permalink.
*/
function sk_image() {
$image_args = array(
'size' => 'custom-square-thumbnail',
'attr' => array(
'class' => 'alignleft',
)
);
// Get the featured image HTML.
$image = genesis_get_image( $image_args );
echo '<a rel="bookmark" href="'. get_permalink() .'">'. $image .'</a>';
}