How do they decide when the sheep gets a reward? To me it looked like it was quite ambiguous sometimes what the sheep was doing, it kind of waddled to the left/

How do they decide when the sheep gets a reward? To me it looked like it was quite ambiguous sometimes what the sheep was doing, it kind of waddled to the left/right and once it was at the right choice it got a reward... Anyone knows how the reward was determined? Was there a person observing? It would be more convincing if the sheep had to commit to a choice by selecting a left/right door it needs to enter based on the information presented.