I think the problem you are having is you are using a 'complex' var in a
simple parse method (double quotes).
Once the engine hit the first closing array index bracket ']', the var
is done being parsed.
Try concatenate with '.'
<?php echo "<img src='" . $list[1]['cover'] . "'>"; ?>
or my favorite, use the complex type parsing with curlies.
<?php echo "<img src='{$list[1]['cover']}'>"; ?>
Scotty