Supported Versions: The details shared here apply to the most recent version of eComm Performance. eComm Performance gives you the option to enable a lock icon for the checkout button. This will appear both on the mini cart and the cart page. This shows customers that your store is secure thanks to Shopify's built-in SSL feature, and it allows you to build trust with your customers.
To enable the icon, head into Customize > Theme Settings > Cart > 'Show lock icon on checkout button':