title: how to change default receiver image size on tv screen
body: <p>I altered the sample code and set the value, and then found that the default receiver image size has no change on tv. how to change that?</p>
  
  <pre><code>GCKMediaMetadata *metadata = [[GCKMediaMetadata alloc] init];
  
    if (thumbnailURL) {
      [metadata addImage:[[GCKImage alloc] initWithURL:thumbnailURL width:200 height:100]]; //&lt;=== alter here,  try to change "width:200 height:100" to "width:720 height:960", but there's no change.
    }
  
    GCKMediaInformation *mediaInformation =
        [[GCKMediaInformation alloc] initWithContentID:[url absoluteString]
                                            streamType:GCKMediaStreamTypeNone
                                           contentType:mimeType
                                              metadata:metadata
                                        streamDuration:0
                                            customData:nil];
    [self.mediaControlChannel loadMedia:mediaInformation autoplay:autoPlay playPosition:startTime];
  </code></pre>