Not as a gimmick. As a demonstration. Everything below the fold is AES-256-GCM ciphertext right now. Your browser will derive a key from the PIN, and open it, or fail.
That is exactly what the app does to your files, except with a PIN nobody printed on the door.
Demo PIN 4021. There is also a decoy PIN, 0000, which opens a different vault. Try both, in that order.
or type on your keyboard · Enter to unlock