Single event meta: add venue thumbnail

add_filter( 'tribe_event_pro_meta_venue_name', 'single_event_venue_thumb' );

function single_event_venue_thumb( $html ) {
    $post_id = get_the_ID();
    $venue_id = tribe_get_venue_id( $post_id );
    $thumb = get_the_post_thumbnail( $venue_id );
    return $thumb . $html;
}