Phones are high fraud scam magnets. (Is your friend also a fairly new seller, possibly with low feedback?)
I suspect what will happen is that if your friend accepts an offer, they'll receive a realistic looking paypal email saying that payment is made and will be released once tracking shows movement.
However the email will NOT be from paypal and the buyer will get a free phone. There'll be no seller protection because she didn't accept an approved payment.
My recommendation would be to block these buyers.
@MAGJES, I'm sorry your buyer was a flake! Except for the ID history, there weren't other red flags. Really, there weren't!