Why are discounts applied to non bundle products in the cart?

Discounts can be applied to products in cart even if they weren't added through a bundle

Once you create a discount in the PickyStory app, it automatically creates a discount code in your Shopify Admin. The discount code is applied to all products that are part of bundles that are linked to the discount. This means that the discount can be applied even if the shopper added the bundled products directly to the cart from the product pages. 

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