Updated requirements for largesize

Author: chrisbloom7

docs/dock/largesize.md

@@ -20,7 +20,10 @@ Set the icon size of magnified Dock items in pixels.
 
 ## Requirements
 
+This setting will have no effect unless the following conditions are met:
+
 - [`com.apple.dock magnification`](/dock/magnification.md#set-to-true) must be set to `true`
+- The set size must be greater than the value of [`com.apple.dock tilesize`](/dock/tilesize.md)
 
 ## Set to `96` (default value)