When you create a vault, Vaultpod shows ten words. That is the recovery phrase. It opens the vault on any phone, with or without the pattern.
Where the words come from
They are picked at random from a list of 7,776 common English words (the EFF long word list). Ten words from that list is about 129 bits of randomness: no computer will guess it. You can type your own six to nine words instead, but a phrase you make up is weaker than one that is random.
Why the app asks you to type two of them back
Because most people tap past the phrase and never write it down. Being asked for word 3 and word 8 right away is a small nudge that saves vaults.
Where to keep it
On paper, somewhere safe. Or in a password manager. Not in a screenshot in your Photos library, which is exactly the place you are trying to protect.
Without it
If the phone is gone and you have no phrase, the backup is unreadable and nobody can help. If you still have the phone and the pattern, open the vault and set a new phrase from Security.