I’ve always wondered if those pictures are real, or just “created” and posted.
If one ever showed-up in my field, I’d have a hard time believing that people could do that, trudging through the field with boards and ropes, over one night ;-)
Some of them are human created. But it is fairly easy to distinguish those.
They say people did it by dragging boards with rope.
If you have seen the closeups of some of these, no board could do it.