Oh, I like this USPS analogy but I'll clean it up. Google photos and chat are like a USPS that only stores and transmits post cards. It's understood by the creator/sender that anyone who has access to them can read them. Apple here is a USPS that sends sealed envelopes. They (say they) can't read what's inside as it's sent or stored. With this change they will create the 'capability' to show up whenever you decide to send an envelope and read it before you seal it up for sending.

Meh, nevermind. That's not much cleaner.