He might have his laptop resolution set to it's highest resolution. If so, then that maybe why his video splitcamera window is small. The maximum resolution splitcam is capable of running at is 2048x1536 aspect ratio. His machine is capable of running at a higher resolution that might have been set at 2560x1440 IPS by default. However, you do have an option that you could try reducing your laptop resolution a bit, and see if that improve things.
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