use-acf-get-field.php

<?php
    $images = get_field('photos');
    if ($images) { ?>
<div class="images">
<?php
        $alt = $images[0]['alt'];
        if (empty($alt)) {
            $alt = $images[0]['title'];
        }
        printf('<a href="%s" itemprop="image" class="main-image zoom thickbox" title="" rel="prettyPhoto[gallery] gallery"><img width="%d" height="%d" src="%s" class="attachment-shop_single size-shop_single wp-post-image" alt="%s" title="%s" /></a>',
               $images[0]['url'], $images[0]['sizes']['featured-image-width'], $images[0]['sizes']['featured-image-height'], $images[0]['sizes']['featured-image'], $alt, $images[0]['title']);

        if (count($images) > 1) {
            $images = array_slice($images, 1);  // Remove first element as it has been output as main image.
?>
	<div class="thumbnails">
<?php            
            foreach ($images as $image) {
                $alt = $image['alt'];
                if (empty($alt)) {
                    $alt = $image['title'];
                }
                printf('<a href="%s" class="zoom thickbox" title="" rel="prettyPhoto[gallery] gallery"><img width="%d" height="%d" src="%s" class="attachment-shop_thumbnail size-shop_thumbnail" alt="%s" title="%s" /></a>',
                       $image['url'], $image['sizes']['thumbnail-width'], $image['sizes']['thumbnail-height'], $image['sizes']['thumbnail'], $alt, $image['title']);
            }  // End: foreach ($images as $image)
?>
    </div>
<?php
        }  // End: if (count($images) > 1) ?>
</div>
<?php    }  // End: if ($images) ?>
</div>

use-tim-jensen-version.php

<?php
  global $post;
	$inflatable_info = get_post_meta( $post->ID );
	$images = maybe_unserialize( $inflatable_info[ 'photos' ][ 0 ] );
    if ($images) { ?>
<div class="images">
<?php
    $uploads_dir = wp_get_upload_dir()['baseurl'];

		$featured_image = get_post_meta( $images[ 0 ] );
		$image_meta = maybe_unserialize( $featured_image[ '_wp_attachment_metadata' ][ 0 ] );
		$image_dir = $uploads_dir . '/' . dirname( $image_meta[ 'file' ] );

		$alt = '';
		if ( array_key_exists( '_wp_attachment_image_alt', $featured_image ) ) {
			$alt = esc_html( $featured_image[ '_wp_attachment_image_alt' ][ 0 ] );
		}
		$title = get_the_title( $images[ 0 ] );
		
		printf('<a href="%s" itemprop="image" class="main-image zoom thickbox" title="" rel="prettyPhoto[gallery] gallery"><img width="%d" height="%d" src="%s" class="attachment-shop_single size-shop_single wp-post-image" alt="%s" title="%s" /></a>',
		   esc_url( $uploads_dir .'/'. $image_meta[ 'file' ] ),
		   esc_html( $image_meta['sizes']['featured-image'][ 'width' ] ), esc_html( $image_meta['sizes']['featured-image'][ 'height' ] ), esc_url( $image_dir .'/'. $image_meta['sizes']['featured-image'][ 'file' ] ),
		   $alt, $title);


    if (count($images) > 1) {
      $images = array_slice($images, 1);  // Remove first element as it has been output as main image.
?>
	<div class="thumbnails">
<?php            
		foreach ( $images as $image ) {
			$image_info = get_post_meta( $image );
echo '<!-- ', var_export( $image_info, true ), " -->\n";
			$image_meta = maybe_unserialize( $image_info[ '_wp_attachment_metadata' ][ 0 ] );
			$image_dir = $uploads_dir . '/' . dirname( $image_meta[ 'file' ] );
			
			$alt = '';
			if ( array_key_exists( '_wp_attachment_image_alt', $image_info ) ) {
				$alt = esc_html( $image_info[ '_wp_attachment_image_alt' ][ 0 ] );
			}
			$title = get_the_title( $images[ 0 ] );
			
			printf('<a href="%s" itemprop="image" class="main-image zoom thickbox" title="" rel="prettyPhoto[gallery] gallery"><img width="%d" height="%d" src="%s" class="attachment-shop_single size-shop_single wp-post-image" alt="%s" title="%s" /></a>',
			   esc_url( $uploads_dir .'/'. $image_meta[ 'file' ] ),
			   esc_html( $image_meta['sizes']['thumbnail'][ 'width' ] ), esc_html( $image_meta['sizes']['thumbnail'][ 'height' ] ), esc_url( $image_dir .'/'. $image_meta['sizes']['thumbnail'][ 'file' ] ),
			   $alt, $title);
		}
?>
    </div>
<?php
        }  // End: if (count($images) > 1) ?>
</div>
<?php
	}