If by power, we mean what level of performance will it deliver? Likely something between PS4 and Series S in terms of graphical features and prowess. Third parties will treat it as a 30fps/720p (or even lower) machine, but the image resolve will be anywhere from 900p to 4k depending on the game/developer. Visual feature set will be closer to the Series S compared to the PS4. PS4 Pro keeps being brought up but that's just a PS4 natively running games at 1440p, Switch 2 will be doing things you will not see onPS4 Pro albeit at a lower internal resolution.
Put Nintendo in charge of a PS4 level device with Nvidia's modern feature set and I'm sure we'll be getting plenty of stylised games that won't out of place on the PS5