We listen for a change event on line 27 in lib/storage.js like so:
```js
this.image.addEventListener('change', this.onStorageChange);
```

We then emit a `'statechange'` event to allow the rest of the app to respond to these changes. If you need a better API than this (perhaps `this.app.set('storageState', <current-state>);`) feel free to implement it :)