Sliders Example - The grey vertical slider seems to be inverted

Description:

The grey vertical slider seems to be inverted. It should be following the blue slider (as it does for the horizontal option), but goes opposite to it for the vertical option.
Steps to reproduce:

1. Open the Sliders Example 
2. Turn the circle or press up/down on the keyboard. (The blue slider and grey slider go in the same direction)
3. Change  "Horizontal slider-like widgets" to "Vertical slider-like widgets"
4. Turn the circle or press up/down on the keyboard. (The blue slider and grey slider go in the opposite direction)

Expected behavior:

The grey and blue sliders should go in the same direction for the vertical and for the horizontal option. 
Observed behavior:

Their direction are opposite when in horizontal mode.
Special notes: