Regardless of hard-coding the height and width or placing them in the database as configurations, the line still retrieves only the DIR_WS_CATALOG (/) and DIR_WS_IMAGES (images). Beyond that - nothing.
Code:
<table border="0" width="100%" cellspacing="0" cellpadding="2">      <tr class="dataTableHeadingRow">
  <!-- BOF Add Image 1 of 2 - dbltoe -->
        <td class="dataTableHeadingContent">Image</td>
  <!-- EOF Add Image 1 of 2 = dbltoe --> 
        <td class="dataTableHeadingContent" align="center">Qty</td>
        <td class="dataTableHeadingContent"><?php echo TABLE_HEADING_PRODUCTS_MODEL; ?></td>
        <td class="dataTableHeadingContent">Option(s)</td>
      </tr>
<?php
    foreach ($order->products as $currentProduct) {
        if ($currentProduct['orders_multiship_id'] != $multiship_id) {
        continue;
        }
?>
      <tr class="dataTableRow">
  <!-- BOF Add Image 2 of 2 - dbltoe -->
        <td class="dataTableContent" valign="top" align="left">
            <?php echo zen_image(DIR_WS_CATALOG . DIR_WS_IMAGES . zen_get_products_image($order->products[$i]['id']), 'Product Image', IMAGE_ON_INVOICE_IMAGE_WIDTH, IMAGE_ON_INVOICE_IMAGE_HEIGHT); ?>
        </td>
  <!-- EOF Add Image 2 of 2 - dbltoe -->
        <td class="dataTableContent" valign="top" align="center"><?php echo $currentProduct['qty']; ?></td>
        <td class="dataTableContent" valign="top"><?php echo $currentProduct['name']; ?>
<?php


        if (isset($currentProduct['attributes']) && (sizeof($currentProduct['attributes']) > 0)) {
            foreach ($currentProduct['attributes'] as $currentAttribute) {
?>
          <br /><span class="nobreak"><small>&nbsp;<i> - <?php echo $currentAttribute['option'] . ': ' . nl2br(zen_output_string_protected($currentAttribute['value'])); ?></i></small></span>
<?php
            }
?>
        </td>
        <td class="dataTableContent" valign="top"><?php echo $currentProduct['model']; ?></td>
<?php
        }
?>
      </tr>
<?php
    }
?>
    </table>
Any more thoughts? Works like a champ with standard packing slip.