The first peak specified for the current waveform is formed by the parasitic capacitance between the discharge gun and the mounting plate.
Because the simplified version has a smaller area than the IEC standard product, the first peak will be slightly lower than specified.
The second peak is related to the routing of the discharge return cable. In the standard, the cable is extended backward at a position 0.5m from the target, but with the simplified version the same extension cannot be made, so waveform changes in the second peak section may occur.