Using ACF for taxonomy images.

acf_term_list.php

<?php

$prod_cats = get_terms( 'product_cat', 'hide_empty=0' );
?>
<ul class="gk-special-menu">
  <?php
  foreach( $prod_cats as $cat ){
      $name = $cat->name;
      $prod_term_link = get_term_link( $cat );
      
      $img_obj = get_field( 'product_cat_img', 'product_cat_'.$cat->term_id );
      
      ?>
      <li data-scroll-reveal="enter bottom over .25s after .5s">
          <h4><?php echo $name; ?></h4>
          <a href="<?php echo $prod_term_link; ?>">
              <img class="alignnone size-full wp-image-974" src="<?php echo $img_obj['url']; ?>" width="185" height="256" />
          </a>
      </li>
      <?php
  }
  ?>
</ul>