Chrome Webapp Splashscreen / Bigger icon

Is there anything I can do to make the splash screen icon bigger and move the text to the bottom like in the Voice Memos Demo?

Voice Memos

My Test App

This is in my head:

<link rel="icon" href="images/icon192.png" sizes="192x192" type="image/png">
<link rel="icon" href="images/icon384.png" sizes="384x384" type="image/png">

and this in my manifest:

 ...
"icons": [
                {
                    "src": "images/icon192.png",
                    "sizes": "192x192",
                    "type": "image/png"
            },
                {
                    "src": "images/icon384.png",
                    "sizes": "384x384",
                    "type": "image/png"
            }
          ],
...