I like the 2 first pictures most, because like the others say, the 2 last looks like some filter applied.
But it REALLY matters if you use photo mode with/without AI, or PRO mode or HDR mode or Aperture mode. You can get all kinds of different pictures from the P20 pro, depending on the mode you choose.
Therefore it's not really possible to compare with another camera, without securing you use a similar mode.