I think it is clever how the "negative space" of the rounded envelope plus how the wing is holding it evokes a "speech bubble" of most other messaging apps, whi

I think it is clever how the "negative space" of the rounded envelope plus how the wing is holding it evokes a "speech bubble" of most other messaging apps, while still being visually an envelope. It's subtle, but communicative, and one of those things that once you see it, is always there (like the FedEx arrow).