James, have you ever considered "cropping" your photographs on the camera? It's not impossible to do, and you end up with a picture that fits the frame you used to make it. When you look through that viewfinder do you say to yourself: "Now let's see. . . how can I make this picture work? Oh! I can crop it there, and there, and there, and it'll end up with a square picture?" Or do you wait until you have the picture out of the camera, on your computer, and say to yourself: "Now let's see. If I crop it here and here and here I'll have a square picture?" Seems to me the time to crop is when you're looking through that viewfinder. If you want square pictures, buy a 2 1/4 x 2 1/4 camera. If you want 4 x 5 pictures, buy a 4 x 5 camera. If you want 4 by 3 pictures, buy a four-thirds camera. I think that's what Jeremy did here. He framed to the viewfinder, and I think he was exactly right. The back field puts the barn in context, and the squiggly line of the beautiful fence introduces you to the structure.
In the second iteration we have two different pictures: the barn, introduced by a fairly short stone fence that blocks the barn door on camera left, and a field in the background camera right. Both are moderately interesting, but they don't belong together. In the third iteration we have iteration number two, plus another whole world in the background that has nothing at all to do with the barn itself.
Jeremy nailed it on the first iteration of this picture. It doesn't need cropping. It doesn't need to be square. It doesn't need anything it doesn't already have. It's a finished product!