This vid just popped up on my search page or whatever it's called on Instagram.
A few people have commented what I was thinking but the girl (and her friend?) seem to think there's nothing wrong with it. She's basically jumping her horse with really long split reins that are dangling around his feet.
I'm horrified tbh - it's so dangerous! If the horse steps on it, or gets the reins tangled around his leg, he's going to flip over.
Not sure about posting the actual video but I've added a screenshot. The reins are hitting the jumps later on in the video!