webbed-site/_includes/layout/gallery/picrew.html

<div class ="image-gallery" style="margin: auto;">
  {% assign images = site.data[include.data_file] %}
  {% assign sorted_images = images | sort: "name" | reverse %}
  {% for image in sorted_images %}
  {% assign alt_text = image.alt | default: "image" %}
    <div class="box">
      {% if image.link != "" %}
        <a href="{{ image.link }}" target="_blank">
          <img src="{{ '/' | append: include.folder | append: '/' | append: image.imgurl }}" alt="{{ alt_text }}">
      </a>
      {% else %}
        <img src="{{ '/' | append: include.folder | append: '/' | append: image.imgurl }}" alt="{{ alt_text }}">
      {% endif %}
    </div>
  {% endfor %}
</div>