<?php
// Wordpress only
the_post_thumbnail('thumbnail', array('itemprop' => 'image'));
// Genesis
$image_args = array(
'attr' => array(
'itemprop' => 'image',
),
);
genesis_image( $image_args );
Featured image code
<?php
// Do not include the above.
if ( has_post_thumbnail() ) { // check if the post has a Post Thumbnail assigned to it.
$image_args = array(
'size' => 'full',
'attr' => array(
'class' => 'alignleft post-image entry-image',
'itemprop' => 'image',
),
);
echo '<div class="entry-featured-image">';
genesis_image( $image_args );
echo '</div>';
}