thumbsup/themes/base/partials/thumbnail.hbs

{{~#if isVideo~}}

  {{!--
    Video thumbnails
  --}}

  <li data-html="#media{{id}}"
      data-download-url="{{relative urls.download}}">
    <a href="{{relative urls.download}}">
      <img src="{{relative urls.thumbnail}}"
           width="{{@root.gallery.thumbSize}}"
           height="{{@root.gallery.thumbSize}}"
           alt="{{filename}}" />
    </a>
    <img class="video-overlay" src="{{relative 'public/play.png'}}" />
  </li>

{{~else~}}

  {{!--
    Image thumbnails
  --}}

  <li data-src="{{relative urls.large}}"
      data-sub-html="{{meta.caption}}"
      data-download-url="{{relative urls.download}}">
    <a href="{{relative urls.download}}">
      <img src="{{relative urls.thumbnail}}"
           width="{{@root.gallery.thumbSize}}"
           height="{{@root.gallery.thumbSize}}"
           alt="{{filename}}" />
    </a>
    {{#if meta.animated}}
      <img class="video-overlay" src="{{relative 'public/play.png'}}" />
    {{/if}}
  </li>

{{~/if~}}