When an issuer uses "Send Preview" on an email template, attributes don't populate in the test email. Both credential-level attributes (like recipient name) and design attributes (like the badge image) come through blank or broken. The only way to see the email as a recipient would is to issue and publish a real test credential to yourself, which adds friction when someone just wants to check a template change. Ideally, the user could populate the necessary attributes and select a preview group to pull in this information.