From Grok :

Stateless Signing Mode: The person you spoke to might be referring to using the Jade as a stateless signing device, which is an advanced, optional mode. In this configuration, the Jade does not store the seed phrase on the device. Instead, you manually enter the seed phrase (or scan a SeedQR code) each time you start a session to load the wallet temporarily. This mode is typically used for enhanced security in air-gapped setups or for users managing multiple seeds (e.g., in a multisig wallet). Once the session ends (e.g., the device is powered off), the seed is not retained, and you would need to re-enter it for the next session. This is not the default setup and is generally used by advanced users who prioritize air-gapped security over convenience.

That's cool !