This is what happens when counter-intuitive terms are used in an attempt to create the condition of half pregnant.
It would make more sense if it were called Pilot Under Supervision Simulating Command.
The pilot being supervised logs PUSSC, and must differentiate that time from actual PIC time, and identify the supervising PIC, in the logbook.
The supervising pilot is the PIC so logs the time as PIC.
Whether the hours criterion for a qualification differentiates between time as PIC supervising PUSSCs and other PIC time: dunno and couldn't be bothered checking.