Hi @shrewdies,
Wow, you’re running Native AMP!

Yes, this looks to be a bug. Thanks for letting me know about it.

I also saw that, where the schema.org data doesn’t have an image value for attachment pages:

https://www.goutpal.com/11607/gout-in-shoulder/shoulder-in-gout-mri-media/

It looks like you’re right that amp_get_post_image_metadata() isn’t getting the data of an image if the page is an attachment page.

I’ll request a GitHub issue for this. In the meantime, placing this in your theme should add the image. It worked for me locally:

/**
 * Add data for an image when the page is an attachment page.
 * 
 * On attachment pages, like pages for an image, there wasn't a schema.org value for 'image.'
 * So this adds it via a filter.
 * 
 * @param array   $metadata The schema.org metadata.
 * @param WP_Post $post     The post to which it applies.
 * @return array $metadata The filtered schema.org metadata.  
 */
add_filter( 'amp_post_template_metadata', function( $metadata, $post ) {
	if ( empty( $metadata['image'] ) && ( 'attachment' === $post->post_type ) ) {
		$post_image_src = wp_get_attachment_image_src( $post->ID, 'full' );
		if ( is_array( $post_image_src ) ) {
			$metadata['image'] = array(
				'@type'  => 'ImageObject',
				'url'    => $post_image_src[0],
				'width'  => $post_image_src[1],
				'height' => $post_image_src[2],
			);
		}
	}

	return $metadata;
}, 10, 2 );

• This reply was modified 5 months ago by  Ryan Kienstra.
• This reply was modified 5 months ago by  Ryan Kienstra.

Also, simply commenting on this GitHub issue and linking to this support topic would be fine:

https://github.com/Automattic/amp-wp/issues/1157