Brine image too small in tablet view

In Brine (Pedro, actually) I have centered an image on an index page (on the page below the index, actually) that looks fine on desktop, fills the screen almost side to side on mobile, and is tiny on tablet view. I'd like to make the image smaller on mobile, and much larger on tablet view. Any suggestions?

Sorry, I can't supply a URL for contractual reasons, I hope this is clear.

Can you share link to index page? We can help easier.

Sorry, I can't supply a URL for contractual reasons. Will create a dummy if I can find the time. Thanks.

Difficult to help without seeing url.