New device

I received this message. What does it mean?

In the Bivreost wallet, your private key that signs your transactions is the device from which you created the wallet. When you try to log in from a new device, you receive this message because you are already in the user database, but the private key is not yet on this device. This is why you cannot log into your wallet. To connect a new device, use your secret phrase that you wrote down earlier.