WordPress: Jetpack snippets

override_jetpack_sharing_image.php

<?php
/**
 * Override Jetpack Open Graph sharing image
 *
 * @link https://jetpack.com/tag/open-graph/
 */
add_filter( 'jetpack_images_get_images', 'override_jetpack_images_get_images', 20, 3 );
function override_jetpack_images_get_images( $media, $post_id, $args ) {

	$root_directory = get_bloginfo( 'stylesheet_directory' );
	$image_path = '/img/social-share.jpg';

	$permalink = get_permalink( $post_id );
	$image_url = apply_filters( 'jetpack_photon_url', $root_directory . $image_path );

	return array( array(
		'type'  => 'image',
		'from'  => 'custom_fallback',
		'src'   => esc_url( $image_url ),
		'href'  => $permalink,
	) );
}