I had the same problem, and Image is requested to validate Schema.org
This is my fix :
– edit the build_metadata() function inside class-amp-post.php and add image information like this :
'image' => array(
'@type' => 'ImageObject',
'url' => wp_get_attachment_url( get_post_thumbnail_id($post->ID) ),
'width' => wp_get_attachment_metadata( get_post_thumbnail_id($post->ID) )[width],
'height' => wp_get_attachment_metadata( get_post_thumbnail_id($post->ID) )[height]
),
You will have to do the same thing with your logo, inside the publisher section (but url, width and height can be static in this case)
I think it worked because the errors from Google structured data testing tool are gone…