Images not visible --> source code tells me that it's showing my normal posts

    <?php
/*
    Template Name: portfolio pagina
*/
?>
<?php get_header(); ?>

        <section class="row">
          <div class="small-12 columns text-center">
            <div class="leader">

            <!-- BEGIN VAN DE LOOP -->
            <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

              <h1><?php the_title(); ?></h1>
              <?php the_content(); ?>

            <?php endwhile;  endif; ?>
            <!-- EINDE VAN DE LOOP -->    

            </div>
          </div>
        </section> 

<?php 

  $args = array(
    'post-type' => 'portfolio'
  );
  $query = new WP_Query( $args );

?>

        <section class="row no-max pad">

        <?php if( $query->have_posts() ) : while( $query->have_posts() ) : $query->the_post(); ?>

          <div class="small-6 medium-4 large-3 columns grid-item">
            <a href="<?php the_permalink(); ?>"><img /><?php the_post_thumbnail( 'large' ); ?></a>
          </div>

      <?php endwhile; endif; wp_reset_postdata(); ?> 

        </section>


<?php get_footer(); ?>

<a href="http://localhost:8888/wordpress_team_tree_house/hallo-wereld/"><img></a>