Same Resolution Icons Appear as Different Sizes

Hello,

I'm going through all of my dock icons and customizing them, but I'm having a bit of trouble.

The five icons on the right, as you can see, are all working fine. However, the icon for Brackets, the application on the left, is strangely larger than all the others.

This is strange, as all of them are 1024x1024 png images, but for some reason, this one icon displays as larger.

Any advice is greatly appreciated.