WPUF Show Attachment Images

<?php
$attachments = wpfu_get_attachments( $post->ID );

if ( $attachments ) {
    $attach = '<ul class="wpuf-attachments">';

    foreach ($attachments as $file) {

        //if the attachment is image, show the image. else show the link
        if ( wpuf_is_file_image( $file['url'], $file['mime'] ) ) {
            $thumb = wp_get_attachment_image_src( $file['id'] );
            $attach .= sprintf( '<li><a href="%s"><img src="%s" alt="%s" /></a></li>', $file['url'], $thumb[0], esc_attr( $file['title'] ) );
        } else {
            $attach .= sprintf( '<li><a href="%s" title="%s">%s</a></li>', $file['url'], esc_attr( $file['title'] ), $file['title'] );
        }
    }

    $attach .= '</ul>';

    echo $attach;
}