Inbox
Snoozed
Important
Feel
The "feel" choice seems to be "sent".
The other change is that the "Compose" button (for starting a new email) is now labeled...
"Compound."
UPDATE: It just switched back to the way it was. I wondered if I'd accidentally clicked some button for a different dialect of English, or if Google is testing some new feature. (Or the interface somehow just dropped in the wrong words?)