I would suggest you create a new style that you can play with and play with the template there.
The image part of the code is here
HTML Code:
<div class="fullwidth article_preview_contents<vb:if condition="$showpreviewonly"> showpreviewonly</vb:if> restore">
<vb:if condition="$showpreviewonly">
<vb:if condition="$previewvideo">
{vb:raw previewvideo}
<vb:elseif condition="$previewimage" />
<a href="{vb:raw page_url}">
<img class="cms_article_preview_image" src="{vb:raw previewimage}" alt="<vb:if condition="$attachment_settings['alt']">{vb:raw attachment_settings['alt']}<vb:else />{vb:rawphrase article_preview}</vb:if>" <vb:if condition="$attachment_settings['title']">title="{vb:raw attachment_settings['title']}"</vb:if> /></a>
</vb:if>
</vb:if>
<div>