The AS350B3e increases NR based on pedal position. It does it for all altitudes.
The Eurocopter THM for this aircraft indicates that the increase is for "good performance in case of engine failure, and increase of maneuverability in high winds." (B3e THM, Rev 05-2011, pp. 13.13).
The increase in NR occurs abruptly, so abruptly in fact that operators have over torqued engines as a result of large pedal inputs when hovering near max torque.