It is roaming Janna Top which was meta back then. She would roam around the map get others fed deny any play enemy would want to make. Enemy top laner can try to get fed by getting platings but this puts him into the risk of getting ganked by enemy jungler and janna. On top of that since Janna is not farming the game decides that the cs difference between top laners is enough to put a bounty on the top laner. Not to mention it is quite tilting for other laners since they are playing the game with a Janna to worry about. If enemy top laner tries to match your roam most top laners are slow and cant match Janna and even if they match it Janna excels at keeping people at bay.
