Please excuse my question, as I am quite design-inept, and often have no problem with whatever visuals are presented. I'm trying to figure out which margins are worthy of ire or inconsistent, for the sake of my own improvement on such visual matters.
The only difference/inconsistency that leaps out at me is that between the content of a window and its border, in which case there seems to be a clear divide between popup/info windows ("Save a Copy", "Color", "Online Accounts") and the more persistent, full-application windows ("Contacts", "Documents" and the image viewer).
There are differences between the spacing of other UI elements, for sure, but I don't really understand why one element should or should not be placed a consistent distance away from another. E.g. in the "Online Accounts" window, the All Settings button has identical top and bottom margins, but it is a different margin from left margin, as well as different from the margin between the white box in the pane below, and its container. Which of these, if any, would you change and why?