It is a birth defect known as Wry nose and can also be genetic. Mainly affects eating, sinus and respiration depending on the severity. Will have hideous teeth!
Redwings have an adoption pony (if he's still alive) called Oliver twist, with the same problem. He had to have expensive dental work on a regular basis but coped well eating etc.
My concern is that the ad says he could be ridden as a leisure horse! Only if you wanted to ride in a headcollar!!! There's no way you'd ever put a bit in the poor boy.
(Perhaps some nutty person following the big 'p' will give it a go eh?? Lmao)
I had a 14.2hh pony on loan once who had a broken nose - really smashed dent on one side of his face. He got it out hunting as got kicked in the face (I know this isn't the case here) but I think it was touch and go at the time. He was a fantastic horse. Fortunately his breathing wasn't affected neither were his teeth. Yes he didn't look pretty but blimey I have never ridden such a fantastic jumper ever, he was a star!
They should have had that corrected when he was younger. It's correctable (pin the longer side to stop it growing so the other side catches up), not particularly difficult to do and would have stopped all the teeth issues he's going to have in later life. He's 3yrs old now, so really a bit late