HTTPS hides all the information that’s sent in the HTTP transaction. It doesn’t hide the fact that you’re connecting to a Google server. And it only hides the information that’s sent as HTTPS—typically, GMail uses HTTPS to protect the transaction where you send your username and password, but after that, nothing is actually encrypted. And even with HTTPS, your network traffic is interceptable—it just isn’t possible to decrypt it in a reasonable amount of time.