message: Bind onImageError in constructor
  Tt uses `this` but wasn't bound anywhere so the error handler was
  just throwing an exception.
diff: @@ -49,6 +49,7 @@ export default class extends React.Component {
  super(props);
  this.onAction = this.onAction.bind(this);
  + this.onImageError = this.onImageError.bind(this);
  this.onImageEnter = this.onImageEnter.bind(this);
  this.onImageLeave = this.onImageLeave.bind(this);
  this.onClientSync = this.onClientSync.bind(this);
  