Size adjustment help - Struggling to get image blocks to be a more friendly size on mobile

Site URL: https://shop.jonathan-gallagher.com/products/overview

I'm using Brine.

I am happy with the layout for tablets and larger, but on mobile I'd like the sizes of the image sections to all be equal, and the smaller size seems to work nicely. Currently it's too large, so doesn't invite scrolling.

url: https://shop.jonathan-gallagher.com/products/overview

password: jonjonjon

I can't seem to find the correct div. Ideally just for this page/collection.

Thanks for any assistance