How to force display of images in the center?

I occasionally see the web player display the image centered, with the episode title below. Most of the time, it displays the image left-aligned.

Is there a way I can force the centered display?

Here are two examples of what I mean.

Left (usual display):

Center (only sometimes):

The last layout is what I would like to force-enable.

The player has responsive break points. The desired format is the mobile viewport. Limiting the width below 400px should produce the desired layout.