Thanks Field In Sight, the part about the system memorizing elevator position cleared it up for me!!
For anyone interested, this is note 1:
The stabilizer is lost. In alternate law, the auto trim function is provided through the elevators. At landing gear extension, switching to direct law, the auto trim function is lost. However, the mean elevator position at that time is memorized, and becomes the reference for centered sidestick position. This is why, in order to ensure proper centered sidestick position for approach and landing, the procedure requires to wait for stabilization at VAPP, before landing gear extension.If this procedure is missed, the flare and pitch control in case of go-around may be difficult.