based on the title, the addendum, and the note,
after watching such error-lacking, pleasure-filled evidence… why are you crying?
I guess her parents were pursuing proof for the 21 grams experiment, but hadn't been successful to the point of using themselves as the test subjects.
the original 21 grams experiment was considered not credible due to sloppy measurements and scarce sampling.
so the purpose of the room is to provide a large sample size for the experiment. by having them repeat it over and over, and SCP-1444-B (the observing girl) has managed to produce the non-faulty evidence for the 21 grams experiment?
about the "paradox of hedoism", it refers to
constant pleasure-seeking may not yield the most actual pleasure or happiness in the long term when consciously pursuing pleasure interferes with experiencing it.
both the parents and the daughter want to seek pleasure by doing the experiment, but the parents failed and ended up killing themselves and don't actually experience the pleasure.
and I guess the daughter is successful and experienced pleasure.