Two questions: How does screen sharing work if: 1. A retina macbook is viewing the screen of a regular macbook (1440x900)? Does it take up 1/4 space of does it disable hidpi mode for that particular window? 2. What if a normal macbook (1440x900) is viewing a retina screen? Will you need to scroll around to see the screen? Is it impossible to fit it onto the screen?