I think somebody trained her to do that. My gelding can open his stall, so can my mare. L like it that way, in the case of an emergency they could escape the barn. BUT, I have a fenced in area right in front of the barn. 1/2 of it is my small orchard, and I let them graze around the trees and clean up the apples and peaches on the ground during the fall.
Normally, they are content to wait for me.
Funny video, anyway--thanks for sharing.