GetWindow Behavior

I thought I understood this. It seems I do not. I created a blank graph using display and positioned it somewhere on the screen.

GetWindow kwTopWin, wsize; print V_left, V_top, V_right, V_bottom
  255  181  677  553
GetWindow kwTopWin, wsizeDC; print V_left, V_top, V_right, V_bottom
  0  0  422  372

I thought that wsize is to return coordinates in points, whereas wsizeDC is to return them in pixels. It seems however, wsizeDC is returning point dimensions of the width and height of the graph window.

Addendum: Yes, on Mac, points = pixels since ScreenResolution is 72. Why are V_left and V_top zero?