It's hard to tell, but are you sure it's not just a matter of the icon being pixel-perfect and resized? I double-checked both the app and checked out the app folder and found the icons to be generated normally.
It seems that a bigger issue is that the text is going to be illegible when downsized. You may notice that the majority of alls don't use text in their icons, and then they do, it's kept to a minimum (single letter or 3-4 very big letters).