Nothing happens to digit dials when orange reset shaft turns clockwise. So the dials can rotate anticlockwise when counting.
Once the reset shaft turns anticlockwise, thanks to its longitudinal groove and violet pawls on the dials, firstly the same digits on the dials are aligned and then the 0 digits are brought to the reading window.
The violets pawls are forced toward the shaft by red springs.
Green pawls are for positioning the dials.