Can you see that the bag is wider at the bottom (which is on top since the bag is inverted) than it is at the opening?
The FBI bag is perfectly oblong, or you could say rectangular.
So then, they responded with another image, this one:
It still looks pyramidal to me, although granted, not as much as before. But wait. Notice that they clipped the bag. The edge of the bag is cropped on top. They couldn't grab the image without cropping the bag? Or, did they crop it deliberately in order to cheat; in order to mislead? Let's restore the edge of that bag.
Now, when you take the width of the top and compare it to the width of the bottom, there is a lot of disparity again. It certainly doesn't look like this:
They are different bags. Completely different bags.