Sadly, I can’t give you any more details as to what exactly was so miraculous about the Loretto Chapel’s miraculous stairway. Maybe it trips up people who want to push past as I’m trying to walk up it. Maybe it feels like it’s going up when really it’s going down. Maybe it’s just a flat walkway with a priest standing to the side telling you that, if you pray really hard, it’ll turn into a staircase.
Really, your guess is as good as mine.