Hallo,
<td valign="top"><xsl:value-of select="img"/></td>
<td valign="top">
  <img>
    <xsl:attribute name="src">
      <xsl:value-of select="img"/>
    </xsl:attribute>
  </img>
</td>
oder
<td valign="top">
  <xsl:variable name="image" select="img"/>
  <img src="{$image}"/>
</td>
MfG, Thomas