How to change product image ratio substore wise?

Add a startup widget in admin > site > startup widgets.

Name : You can provide any name according to remembrence.
like: 'Change image ratio'

Template: Add the code/examples given below in template acxcording to ur requirement and save.

Examples:

1. If your substore name(alias) is 'abc' and you want to show a rectangle image in abc substore than put the image accordingly and change the image ratio like : 3:1

<div ng-if="ms.user.store == 'abc' ">
  <div ng-init="ms.variables.product_image_ratio = '3:1'">
</div>

2. If your substore name(alias) is 'xyz' and you want to show a square image in xyz substore than put the image accordingly and change the image ratio
like : 1:1

<div ng-if="ms.user.store == 'xyz' ">
  <div ng-init="ms.variables.product_image_ratio = '1:1'">
</div>