Customize line items in Checkout and Customer Accounts order summary using new Checkout Branding API settings

As of Dec 4th, 2024, you can use the settings under checkoutBrandingInput (see: merchandiseThumbnail) in the Checkout Branding API to modify the appearance of line items in Checkout and Customer Accounts order summary for Shopify Plus merchants.

These line-item customizations include the ability to configure custom aspect ratios for product thumbnails, adjust image fit, and modify the background color of quantity badges. 

Note: The aspect ratio setting is only available on the current unstable release. 

Learn more under checkoutBrandingInput in the Checkout Branding API documentation.