Black area on side of artist photo banner

Apologies if this issue has been resolved, but the “black box” issue still persists with me. I use Roon Remote on my Macbook Pro (13-inch) and every artist page looks like this:

Is there a way to resolve this? I tried resizing the window but to no avail.

Other than this, I’m warming up to Art Director’s potential. Everyday and my artist page is looking more and more clean.