In the first case, the 1D vertical line is the same, but it's "seen" from a different angle. It looks the same because it's 1D and it doesn't happen to change b

In the first case, the 1D vertical line is the same, but it's "seen" from a different angle. It looks the same because it's 1D and it doesn't happen to change because of the rotation. For the second case, maybe it's the ground plane that's the same; it certainly has some of the initial texture in it, but it's been rotated and it's now seen from a different angle. But now we can tell the different because it varies along the dimensions it rotated around. Or maybe I just can't visualize the rotation through the fourth dimension... I'm not sure.