How can you tell the difference b/w dark pattern and deceptive pattern?

The online voter registration site for Texas feels like a dark pattern because the use of a familiar Submit button makes it appear like you are registering online but it's actually just a Print function.

Screenshot: https://www.reddit.com/media?url=https%3A%2F%2Fi.redd.it%2Fechvpkj47ggd1.jpeg