Unity 3D just shows orange square when resizing window. And since I'm not native english speaker, here is a screenshot showing what I'm trying to explain:
I can't really answer your question in terms of why there's a difference, but I can tell you how to change the Unity 3D settings to give you your "real time" redraws.
The 'Normal' setting is the one you want, giving you real time updates of the window during resize. On my machine though this is painfully slow.
The Rectangle and Outline are very similar and draw a box representing the resized window.
Personally I like the 'Stretch' option, which gives you a faked-update of the window contents by simply stretching them.
Hope that helps.
