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>