Add: Nap time
Bunya loves to settle into the rounded corner at the gate to their pen.
Here, after noshing on a few treat crumbs in front of him, he first settles into the classic "bunny loaf" position. If he had been on the fireplace, he might have stayed in that position until ... well, someone waves a treat at him (or he hears a snack bag of any type crumpling anywhere, even if it's for the humans).
But in this case, he had to conform to his "corner" and so shortly after he assumes the loaf position, he flops his butt over like he has independent rear suspension.
Which I guess he does.