Authentic espresso takes into account the grind size, extraction time, the beans used, the ratio, tamping, temperature, and more, which you can't achieve with a Nespresso.
An authentic espresso shot includes crema, a golden froth created by the hot pressure of an espresso machine that carries the beans' fullest flavors and aromas.
A Nespresso Vertuo works by spinning and infusing the coffee grounds with water. The motion is what recreates the foamy texture on the top, not any kind of pressure or technique.