Why does the human skin steal field lines when it's very non-conductive in dry state?
It's a capacitive touchscreen (not resistive) and it uses AC pulses to detect the capacitance of the human body. The thin layer of outer skin on the body may indeed be quite non-conductive but the glass which the field projects thru is hundreds (or thousands) of times more non-conductive so clearly the skin's low conductivity isn't of vital importantance in this scenario.