Something isnt right here

Okay I had a curiosity of going into a custom game and standing at the fountain and just letting minions battle it out, what would happen? This is what has happened so far, I didn't want to sit in a game for over an hour to see the end result but after just 16 minutes it was pretty clear. I personally figured the lanes would stay froze out from the start and it would go nowhere. But after a few minutes watching bot and top lane just continuously get shoved into the enemy towers i stayed around longer. From the picture in the link it is pretty obvious but i never left the fountain. I have no cs, no experience or anything so I didn't influence this at all.