Modify Jetpack's Open Graph Output

jetpack.open.graph.php

<?php 
/**
 * Modify Jetpack's Open Graph Output
 */
function ef_og_tweaks( $tags ) {
	if ( is_home() ) {
		// Remove the blank image
		unset( $tags['og:image'] );
		
		$ef_og_home_img = 'YOUR_IMAGE_URL';
		$tags['og:image'] = esc_url( $ef_og_home_img );
	}
 
	return $tags;
}
add_filter( 'jetpack_open_graph_tags', 'ef_og_tweaks' );