To be honest that security method doesn't makes sense to me, because if someone has physical acces to the phone and knows PIN, he can just enter PIN in app he will have access to the decrypted wallet just the same like if decryption without blund oracle wouldn't take place ...
I am not very educated in computers but it just isn't logical to me
I understand what you are saying. To be honest, I am confused with their answer as well. I have asked them more questions after their initial reply. I will share here what they say if it's something worth adding. They seem to have confused using the Blockstream app as a companion app to the Jade with creating a hot wallet on the software. I have asked them how the interaction with the blind oracle will prevent a malicious third party who knows the PIN of the wallet from accessing it and stealing the coins. The software can't differentiate between me and you to know who is the legitimate owner and who is trying to steal from someone else's wallet.