Left is what Unity created (with it set to ‘truecolor’). Right is what I exported from photoshop. You can tell the difference on the device, too (just replace the icon file(s) in the xcode project). Is there a reason for this? Unity’s is smaller in file size but I haven’t read about any size limitations for icons yet. Thoughts?
edit: the effect is more apparent with more complex icons
At a guess, Unity just does simple bilinear filtering on the source image when reducing the size for the icon, whereas you’d use better filtering in Photoshop.
You shouldnt have to, and its often better just to write all 4 icons. 512, 114,72,57. Make sure to use GUI settings on the those textures otherwise it will round them up to 64,128 etc