当图像附件插入但未更新时，可以尝试以下操作来清除其标题：

/**
 * Empty the image attachment\'s title only when inserted not updated
 */
add_filter( \'wp_insert_attachment_data\', function( $data, $postarr )
{
    if( 
        empty( $postarr[\'ID\'] ) 
        && isset( $postarr[\'post_mime_type\'] )
        && wp_match_mime_types( \'image\', $postarr[\'post_mime_type\'] ) 
    )
        $data[\'post_title\'] = \'\';

    return $data;
}, 10, 2 );