Proper sized image(responsive images) and how to handle this for shopify
Identification for Responsive image
Tools like GT matrix, lighthouse, Page speed insights
For each image on the page, Lighthouse compares the size of the rendered image against the size of the actual image. The rendered size also accounts for device pixel ratio. If the rendered size is at least 4KiB smaller than the actual size, then the image fails the audit.
Specify multiple image versions and the browser will choose the best one to use: