It will take your double-width PDF file, split it in half, render the
left half to the audience (via a beamer) and the right half - which will
contain the notes you entered in your LaTeX source - on your laptop
In addition, your laptop screen will contain some counters and a
wall-clock, which may help you time your presentation right.
Both screens will be rendered and scaled completely independent of each
other, so you can use two screens with different resolutions and/or
aspect ratios, such as your 16:10 laptop screen and a 4:3 beamer, or the
other way around. Please use both devices’ native resolutions for
maximum image quality.
For this to work the graphic card should support a dual screen.
lspci -nnk | grep VGA -A1
GA compatible controller : Intel Corporation Mobile 4