It's just a crossing. There are plenty more crossings just as busy in Tokyo, but for some reason, this one is super famous.
It's kind of cool though when you first see it. Though after the first viewing it just becomes a very busy crossing (At least in my experience).
It is quite cool to see all the "Cool" kids gather on all sides of this crossing, where model agencies send people to scope out potential models.
Though having a plethora of tourists constantly stopping and taking photos gets very, very, annoying. If you want to take photos, don't stand in the way of everyone, people have things to do yo!
Though at the end of the day the crossing is pretty cool. Perhaps I just take it for granted.