Mobile publication cover photo question

How do I optimize the publication cover photo for mobile?

Desktop is normal, while mobile (below that) renders oddly. I understand why that is, just want to figure out how to institute a mobile-only photo.

The mobile photo:

I’d take a look at css @media queries, and change which image (supposing it is getting loaded as a background image) is used based on screen width.

You may also want to consider switching that text that’s part of the image currently to being actual text, to reduce the chances of it getting cut off depending on screen size.