If you press F12 whilst mousing over PivotUp1 you will be taken to the point in code where PivotUp1 is identified.
When you ask what is inside PivotUp[0] all I can say is -> values.
what does * 1 * TickSize -> when you multiply by ticksize you turn points into ticks
eg. 1 tick on ES is 0.25 points, tickssize is 0.25 therefore to go from ticks to points you multiply whatever number of ticks you got by ticksize to get points.