It's better to use the "Let ```<var>message</var>``` be a new instance of SmsMessage ... ", otherwise it's not really clear in which context the new instance is to be created (should I create this in the instance in global scope?). "Let" also implies that it's only for this algorithm's scope. It also makes more sense when making statements like this:

> Set the <code>type</code> of the <code>SmsMessage</code> to 'sms'.

Because in the assertion above, you are referring to the SmsMessage Interface Object and not the instance you created.