svg image boundary

HTML

<script src="//cdn.jsdelivr.net/snap.svg/0.1.0/snap.svg-min.js"></script>
<svg id="svg" version="1.1" xmlns="http://www.w3.org/2000/svg"></svg>
<div id="logger"></div>

CSS

#svg {
    height: 200px;
    width: 400px;
    border: 1px blue solid;
}

JavaScript

var s = Snap("#svg");

var image = s.image('https://upload.wikimedia.org/wikipedia/en/2/24/Lenna.png', 
                    0, 0, '400px', '200px')
    .attr('preserveAspectRatio', "xMidYMid meet");
document.getElementById('logger').innerHTML = "Left: " + s.node.offsetLeft;