gistfile1.txt

<div id="container">
  <?php
    $rows = get_field('repeater' ); // get all the rows
    $first_row = $rows[0]; // get the first row
    $first_row_image = $first_row['image_1']; // get the sub field value

    $image_small = wp_get_attachment_image_src( $first_row_image, 'thumbnail' );
    $image_full = wp_get_attachment_image_src( $first_row_image, 'full' );

    ?>
    <a class="image-link" href="<?php echo $image_full[0]; ?>">
      <img src="<?php echo $image_small[0]; ?>" width="<?php echo $image[1]; ?>" height="<?php echo $image[2]; ?>"/>
    </a>
</div>