Find something you agree upon. You could appeal to her energy saving mindset.
For example mention how much power an always on computer is drawing and say that videos use CPU which ramps up the wattage and usage. Bright monitors use more energy than dim ones etc. Sleep mode vs always on.
If you want to go even further you could mention the carbon footprint of youtube and internet servers but this is pushing it a bit.
For example mention how much power an always on computer is drawing and say that videos use CPU which ramps up the wattage and usage. Bright monitors use more energy than dim ones etc. Sleep mode vs always on.
If you want to go even further you could mention the carbon footprint of youtube and internet servers but this is pushing it a bit.