DAWN 10.0 ADJUS WHERE TEXT GOES ON BANNERS design

I was able to get the desktop and mobile images uploaded and working, Dawn 10.0. What I have noticed, my desktop banner to be 1600x619 (on the smaller side) and mobile is 800x1279 (larger) I would like to have my desktop image small, or natural size, and mobile large, or natural size. And for mobile put the copy as close to the top of the banner as possible to fit everything. Shopify renders the mobile image at like 390x395 so it appears it is treating the second image as a mobile only but giving it the size of a side by side images, I think? Please see attached.

What I am asking is how do I make the sizes of the banners what I want, and move where the copy goes on the mobile version, and where it breaks on the desktop.

Yes, sorry! I’m doing it in a test theme so I don’t destroy my published theme.

https://s171hpjnwtzhfql3-79280701732.shopifypreview.com/pages/simply-sleep-launch-offer

https://s171hpjnwtzhfql3-79280701732.shopifypreview.com/

store domain (where it will be) shoplivingsimply.com

I am copying a store banner sizes, I love the way they populate and look. I looked at this on their site, I am not sure if it means anything, or not. But I thought I would provide what I am trying to do.