The ring could be a security 'factor' that relies on physical possession, like the Trezor.
Example: You have a bitcoin wallet on your mobile. You want to make a payment. You scan a QR code, Your wallet requests your BIP-38 encrypted key from your ring. You present it and the payment proceeds.
The only difference is that the ring wouldn't sign the transaction, the wallet would still do that, but it wouldn't do it without the ring.
If you lost the ring you would need to turn off 2-factor authentication temporarily until you got another ring. You might get your 'phone snatched, but without the ring the wallet would be useless and you could recover your bitcoin from a backup of your private key.