How does Subscribe appear for logged in vs. logged out users?

What a reader sees in the Subscribe form(s) is a bit different if they are logged in versus if they're logged out of Grow.

Logged In To a Grow Account

When a reader is logged into Grow they will only see a Subscribe button, they won't have to enter their email address: 

Logged Out of a Grow Account

When a reader is logged out of their Grow account, they will be prompted to add their email with the text box: