You may need to adjust depending on your cart version but this code will show manufacturer image. Put it in skin1/customer/main/product.tpl where you want it to show
Code:
{if $product.manufacturer ne ""}
<a href="manufacturers.php?manufacturerid={$product.manufacturerid}"><img src="image.php?id={$product.manufacturerid}&type=M" alt="{$manufacturer}" /></a> <a href="manufacturers.php?manufacturerid={$product.manufacturerid}">See All Products</a>
{/if}