if you wish to display the Cardiff icon at 10% from the left border and at 5% from the top border, modify the previous source and replace the left and top attributes.
<smil>
<head>
<layout>
<root-layout width="600" height="600"
background-color="white" />
<region id="cardiff_icon" left="10%" top="5%"
width="533" height="250" />
</layout>
</head>
<body>
<img src="cardiff.gif" alt="The Cardiff icon"
region="cardiff_icon" />
</body>
</smil>