ADD FEATURED IMAGE TO POSTS LIST VIEW

add_filter('manage_posts_columns', 'featured_image_add_column');

function featured_image_add_column($columns) 
{
  $columns['featured_image'] = 'Product';
  return $columns;
}

add_action('manage_posts_custom_column', 'featured_image_render_post_columns', 10, 2);

function featured_image_render_post_columns($column_name, $id) 
{
  if($column_name == 'featured_image')
  {
    $thumb = get_the_post_thumbnail( $id, array('product-linked-thumb') );
    if($thumb) { echo $thumb; }
  }
}

For CPT, add the CPT name to these lines:

add_filter('manage_MYCPT_posts_columns', 'featured_image_add_column');

// AND

add_action('manage_MYCPT_posts_custom_column', 'featured_image_render_post_columns', 10, 2);