Create or replace with the below content and put it in app\design\frontend\Your-Package\Your-theme\template\catalog\product\view\attributes.phtml
Also make logo named as CE.png,CLASSE II.png, ENEC.png, F.png, IP20.png and place it in skin\frontend\Your-Package\Your-theme\images
<?php
$_helper = $this->helper('catalog/output');
$_product = $this->getProduct()
?>
<?php if ($_additional = $this->getAdditionalData()): ?>
<h2><?php echo $this->__('Additional Information') ?></h2>
<table class="data-table" id="product-attribute-specs-table">
<col width="25%" />
<col />
<tbody>
<?php foreach ($_additional as $_data): ?>
<tr>
<th class="label"><?php echo $this->escapeHtml($this->__($_data['label'])) ?></th>
<?php if ($_data['code'] == "certification_mark"): ?>
<?php $values = explode(',', $_helper->productAttribute($_product, $_data['value'], $_data['code'])); ?>
<td class="data">
<?php foreach ($values as $value): ?>
<div style="float:left;"><img src="<?php echo $this->getSkinUrl("certification_marks/" . trim($value) . ".jpg") ?>"></div>
<?php endforeach; ?>
</td>
<?php endif; ?>
<?php if ($_data['code'] != "certification_mark" ): ?>
<td class="data"><?php echo $_helper->productAttribute($_product, $_data['value'], $_data['code']) ?></td>
<?php endif; ?>
</tr>
<?php endforeach; ?>
</tbody>
</table>
<script type="text/javascript">decorateTable('product-attribute-specs-table')</script>
<?php endif; ?>
It is working for me. Let me know once you tried it.