GD库 - 无法输出到浏览器（Laravel）

So I have a weird issue using the GD library inside Laravel. I can save the file correctly. Base64_encode returns the correct image. But I cant for the life of me get it to show in the browser. In my TestController I have the following:

<?php

namespace App\Http\Controllers;

use App;
use Response;

class TestController extends Controller
{
    public function index()
    {

      $test = imagecreatetruecolor(300, 300);
      $background = imagecolorallocate($test, 0, 0, 0);
      imagefill($test, 0, 0, $background);
      ob_start();
      imagepng($test);
      $buffer = ob_get_contents();
      imagedestroy($test);
      ob_end_clean();

      $response = Response::make($buffer);
      $response->header('Content-Type', 'image/png');
      return $response;
    }
}

That just returns a broken image.

The Console shows the correct headers. I'm pulling my hair out...

So stupid. Found a space before the php tag in my package's config file. I really can't believe it was something so stupid.