The content of the email can be changed in the EME GDPR preferences.
So in fact it is a 2-step procedure:
If the url you give to people contains the parameter eme_email (with value a valid email address), that email will be used to prefill the email field in the resulting form.
2) after the user enters his email and submits the form, he/she gets an email with a link that gives final approval to store personal data.
The page containing this shortcode can then also be sent to all people that haven’t approved yet (from within the people admin overview), in order to ask for their approval.
Note: if the page that contains this shortcode has a parameter eme_email in it (e.g. firstname.lastname@example.org ), then that email will be used to prefill the email field. This allows you to mail the url to this page (via EME) to a lot of people and have their email already filled in (so less work for the receiver).