Most shots are better because of the smaller aperture (you see light in all these shots was creating a shading effect on the bigger F2.2 sensor.
I'll try to demonstrate
Lets say that this is the sensor ")"
And This is the aperture "=" Aperture ( think of it as a cone surrounding the sensor to stop light from hitting it indirectly. )
Lumia 1020's case )=
Lumia 1520's case )==
So colors look washed out because the sensor can read the light hitting the sensor side ways.
I BET that if the guy used a cup or any physical aperture to produce these photos, they'll look miles better.