I made this for the coppercoins site, but they didn't need it. When trying to match up the doubling, it is easier with all the dies on the same sets of images. Then you see the hub doubling/ or the lack of hub doubling.
All the doubling must be the same if they are from the same dies.If one area doesn't match, it is not from that area. Want an example?
Here is an example of a doubled die compared with a normal coin.

Here is a different example from two different dies. Looking at one on this area and checking the second one, makes you think they are the same?

But side by side they are hard to tell apart?
But taking the grand tour of the other areas of the devices, we can see that they are different.


So taking that grand tour helps us to see the differences. Seeing images with a side by side of a normal coin and a coin in question will also help you see or realize it is a normal coin.



So seeing the images side by side helps you to study a coin. Because going form image to a different image, the eyes loose perspective. Thus the side by sides help a lot more.