That doesn't actually mean anything. Resistive and infrared touchscreens (especially cheaper ones) can have all sorts of hilarious calibration errors where part of the screen area works perfectly fine, but other parts of the screen are off completely.

I used to work on kiosk software for restaurants. At the start of every day we had to go through all of the touchscreens in the restaurant and calibrate them. Sometimes they would lose their calibration halfway through the day and need to be recalibrated multiple times.