wp_query, give first post different formatting

Hope I’m understanding you correctly could you not just do something simple like this

$args1 = array(
    'post_type' => 'post',
    'posts_per_page' => 4
);
$loop = new WP_Query($args);
while ($loop->have_posts()) : 
    $loop->the_post();
    echo '<h2><a href="'.the_permalink().'">'.the_title().'</a></h2>';
    if ($loop->current_post == 0) {
          echo the_post_thumbnail();
          echo the_excerpt();
    }
endwhile; wp_reset_postdata();