If you want to round the corners of product photos and thumbnails on the product information screen of the Shopify theme "Dawn/Rise," you can do so without coding or customization by going to the "Settings" section of the theme editor.
Example of setting the rounded corners of product images, collection images, and blog list images in the theme "Rise/Dawn"
[Change the rounded corner size of product images] Can be set from Settings > Media
[Change the rounded corner size of collection images] You can change this setting from Settings > Product Card
[Change the rounded corner size of the blog list image] Can be set from Settings > Blog Card
