Change PDP Image Size On Mobile Dawn Theme

i am trying to change the product image size for my products on mobile dawn theme. i see articles only showing how to change the size for desktop - is it possible to just change the image size for mobile screens?

The two main reasons why image sizes are very important in a Shopify store are:

  1. Loading Speed – the smaller the images, the quicker your store loads and your customer can get what they want.
  2. The Visual Appeal Factor – images larger than the recommended size for a theme will be cropped out. This can make your store look not the way you expected and even lead customers away.

Most Shopify themes are easy to implement and make your store stand out. However, each of them lays out images differently. Ensuring the subject of the image is close to the center will avoid any cropping of the important parts of the image. And below you’ll find the recommended image sizes for some of the most popular Shopify themes. According to Shopify, stores should never have images that are too small or large. While Shopify allows users to upload images up to 4472px X 4472px, image sizes of 2048px X 2048px are highly recommended. Read on for the best image sizes to compliment your store’s theme. Read more

i am trying to make the image look smaller on a mobile screen, to show more before the fold. it is only giving me the option to change desktop. same if i change the CSS, it only changes it on desktop, when mobile is what i am trying to change.