<type name="PayPal\Braintree\Block\Paypal\Button">
    <arguments>
        <argument name="data" xsi:type="array">
            <item name="template" xsi:type="string">
                PayPal_Braintree::paypal/button.phtml
            </item>
            <item name="alias" xsi:type="string">
                braintree.paypal.mini-cart
            </item>
            <item name="button_id" xsi:type="string">
                braintree-paypal-mini-cart
            </item>
        </argument>
        <argument name="payment" xsi:type="object">
            BraintreePayPalFacade
        </argument>
    </arguments>
</type>

This is a type configuration.

This configuration is for the frontend area. This is the area that corresponds with the cart sub-application.

This configuration tells the Object Manager that when a user wants a PayPal\Braintree\Block\Paypal\Button object that the following arguments should be used in the foo object's constructor.

• $data = [...items...];
• $payment = new BraintreePayPalFacade (...)