The "Slideshow" section of the Shopify theme "Dawn" allows you to specify only one image per block, so the same image will be displayed on all devices, with only slight differences in cropping. However, you will probably want to display a vertically long image on a smartphone, so here is an example of how to set it up.
How to set up smartphone images in the "Slideshow section" of Dawn
① Modify the "slideshow.liquid" schema, ② Modify "ja.schema.json"
③ Edit the code where the image is displayed in "slideshow.liquid" & modify the CSS as necessary.
