I thought I was just taking a video of the sheep, walking into the pasture. It wasn’t until I watched the video that I saw Bud herd Izzy back into the pole barn.
I imagine Bud was trying to get Izzy to be with the rest of the sheep, he does usually seem to want to keep them together.
But I really have no idea what Bud is doing. He might just be in it for the chase.