How to display all images “Uploaded By” an author

You can do it via WP_Query loop:

$args = array(
   'author'      => $author_id, // Replace with author id
   'post_status' => 'any',
   'post_type'   => 'attachment'
);
$query = new WP_Query( $args );

More info how to use WP_Query: Codex WP Query