Because of the extremely high pixel density of a retina display, creating a video with pixel-perfect retina graphics will require you to have a really big monitor. The is because monitors have far less pixel density than an retina display. The best way to accomplish your video is to use the non-retina simulator.
If you really need to have the full retina resolution and have a large enough monitor to display it, you can get retina graphics with the nice 4s overlay by using a third part app call Reflection. You can check it out here: http://www.reflectionapp.com/
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solved iPhone 4s looking simulator