The long and short of it is this, we allow you to put interactivity directly inside of your recipients inbox. That means things like slideshows, hot spots, full forms and more.
Our API allows developers to send these emails programmatically, just send just the content of the email in a request. We then build the email on the fly and allow you to send it out.
And SES is already supported via SMTP. We should make that more clear there.