wechat-dump/wechat/static/TP_IMG.html

<div class="chatItem {sender_label}">
  <div class="chatItemContent">
    <span class="avatar"></span>
    <div class="cloud cloudImg">
      <div class="cloudPannel" title="{time}" {nickname}>
        <div class="cloudBody">
          <div class="cloudContent">
            <span class="img_wrap">
              <a class="fancybox" rel="group" href="">
                <img class="zoomIn imageBorder" src="data:image/{img[1]};base64,{img[0]}"/>
              </a>
            </span>
          </div>
        </div>
      </div>
    </div>
  </div>
</div>