public function showMapImage(Request $request)
    {
        // The RecordedGame constructor accepts SplFileInfo instances,
        // so uploaded files can be passed straight to it:
        $rec = new RecordedGame($request->file('game'));

        // `mapImage()` returns an instance of \Intervention\Image, which has a
        // Laravel-compatible `response()` method.
        return $rec->mapImage()->response('png');
    }