尝试以下操作：

$args = array(
    \'name\'=>\'header-images\',
    \'posts_per_page\' => 4,  
    \'orderby\' => \'rand\'
);

即使用posts_per_page 而不是numberposts 如果要使用query_posts() 根据Codex页面：

http://codex.wordpress.org/Function_Reference/query_posts

Edit:

以下是一个想法-使用给定的slug从页面内容中获取库短代码ID：

/*
* Get an array of the gallery shortcode ids from a page content with a given slug 
* @param string $slug Post slug.  
* @param string $type Post type.  
* @return array Array of the exploded ids parameter.
*/
function get_gallery_ids_wpse_87978($slug,$type){
        $output=array();
        $my_query = new WP_Query(array(\'name\'=>$slug,\'post_type\'=>$type));
        while ($my_query->have_posts()) : $my_query->the_post(); 
            $content=get_the_content();
            preg_match(\'/ids=\\"([0-9,]+)\\"/i\', $content, $matches);
            if(isset($matches[1])){
                $output = explode(",",$matches[1]); // let\'s take the last set of ids
            }           
        endwhile;
        return $output;
}       

用法示例：

假设我们有一页有鼻涕虫my-gallery-demo 内容中有这样一个短代码：

[gallery ids="1376,1375,341,213,211,210,209,208,206,205"]

要显示4 随机的thumb 通过此短代码中的图像，我们执行以下操作：

// initial values:
$slug=\'my-gallery-demo\'; // EDIT post/page slug that contains the gallery shortcode 
$type=\'page\'; // EDIT post type (post,page,...) 
$size=\'thumb\'; // EDIT image size (thumb,large,full,...)
$n=4; // EDIT number of random images to show

// fetch all ids from the gallery shortcode:
$ids=get_gallery_ids_wpse_87978($slug,$type);

// get n random keys from the $ids array:
$random_ids=array_rand($ids,$n);

// display a list of n random images:
echo \'<ul>\';
foreach($random_ids as $random_id){
      echo \'<li>\';
      echo wp_get_attachment_image( $ids[$random_id], $size );
      echo \'</li>\';
 }
echo \'</ul>\';