at the time of writing, ReactionCommerce comes with 4 image sizes out of the box. When ImageMagick is installed, all uploaded images should be resized into those 4 formats.
- image: “1000px x 1000px”
- medium: “600px x 600px”
- small: “235px x 235px”
- thumbnail: “100px x 100px”
These formats will be used in different templates for displaying the product images in the browser. This means, that the original image should be at least 1000px x 1000px, but it will not be served directly to the client, AFAIK.
You’ll find the corresponding code in /lib/collections/collectionFS.js