Attach (recommended) or Link to PDF file here:
[backgroundimage_not_visible_anonymisiert.pdf](https://github.com/mozilla/pdf.js/files/6544725/backgroundimage_not_visible_anonymisiert.pdf)


Configuration:
- Web browser and its version: Chrome Version 90.0.4430.212 (Offizieller Build) (x86_64)
- Operating system and its version: Windows 10, MacOs BigSur
- PDF.js version: 2.5.207
- Is a browser extension: no

Steps to reproduce the problem:
1. open the document in demo viewer.js
2.

What is the expected behavior? (add screenshot)
The backgroundimage gets rendered like in Acrobat Reader
<img width="1348" alt="Bildschirmfoto 2021-05-26 um 09 44 21" src="https://user-images.githubusercontent.com/1286150/119621970-00a82480-be07-11eb-8fed-f74ac04b840b.png">

What went wrong? (add screenshot)
Backgroundimage is not rendered only some  text
<img width="987" alt="Bildschirmfoto 2021-05-26 um 09 43 57" src="https://user-images.githubusercontent.com/1286150/119621938-fab24380-be06-11eb-92ac-4ecb2c9334b1.png">




Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

return this._getLineWidth();
      },
    });
  } catch (_) {}
  Object.defineProperty(ctx, "mozCurrentTransform", {
    get: function getCurrentTransform() {
      return this._transformMatrix;
    },
  });
  Object.defineProperty(ctx, "mozCurrentTransformInverse", {
    get: function getCurrentTransformInverse() {
      
      
      
      const [a, b, c, d, e, f] = this._transformMatrix;
      const ad_bc = a * d - b * c;
      const bc_ad = b * c - a * d;
      return [
        d / ad_bc,
        b / bc_ad,
        c / bc_ad,
        a / ad_bc,
        (d * e - c * f) / bc_ad,
        (b * e - a * f) / ad_bc,
      ];
    },
  });
  ctx.save = function ctxSave() {
    const old = this._transformMatrix;
    this._transformStack.push(old);