GS mini = Vapp - Tower Wind(Wind Entered on the Perf Page) + Real Wind (Wind Read Out From Your ND from your ADRS)

Example: Vapp is 130 and Tower Wind is 15 Knots and Real Wind is 25.

GS mini at your Altitude is 130 - 15 + 25 = Equals 140 Knots Ground Speed Mini. As you come down the Glide Slope it will change as the wind changes, unless wind is constant but rare. All designed to keep your Ground Speed Constant to avoid being behind the "curve" in case of wind gusts or wind shear.