In WordPress I am trying to get a page list with their thumbnails, but only pages with a certain custom field. I can get the list, but not their thumbnails. This is what I have so far:
<?php wp_list_pages( 'meta_key=mypagetag&meta_value=crew&depth=2&title_li=&get_the_post_thumbnail=1' );?>
&get_the_post_thumbnail=1 is not a valid argument in wp_list_pages
what I suggest you doing is add a custom walker to your wp_list_pages
check out this tuturial