Ok - here are some pictures to better explain - As you can see below, the top portion of the picture represents the bottom of the heatsink and the thermal material on both heatsinks - The bottom portion represents the side with the locking mechanism (black lever).
Let's start with the top part - Notice that the interface material has a bigger coverage to the left, and to the right it seems the area is smaller. Now both have the SAME part number, the boxes look identical - Now it's obvious that the transfer material on one of those won't fully cover the processor, now someone DID mention AMD cutting corners - well guess LITTERALY

Anyways, that said I am not much concerned about this part (although if someone is, please let me know)
Now the bottom - As you can see the top portion of the heatsink to the left is beveled and the black lever is big (this is usually the ones I see when installing processors). The one to the right (first time seeing this one) has a smaller lever, and the shape is slightly different (different numbers as well)
Now back to the one on the left - The 4 retaining screws on the fan (top part) are not there, the holes are deep and I cannot find anything in there - It is held in place by something under it, cannot remove it - it is slightly loose, I mean if you lift by the fan slightly, you will notice it moving just a bit - whereas the one on the right is tight and is retained by the 4 screws, and yes both fans have an AMD sticker on them.