l_img_col</th>
      <td><p>which column (if any) is a panel image column?</p></td>
    </tr>
    <tr>
      <th>self_contained</th>
      <td><p>should the Trelliscope display be a self-contained html document?</p></td>
    </tr>
    <tr>
      <th>thumb</th>
      <td><p>should a thumbnail be created?</p></td>
    </tr>
    <tr>
      <th>split_layout</th>
      <td><p>boolean that determines if the layout is split into components like a facet_grid vs. individual panels like facet_wrap.  Only applies to g