TIL, Aya here is, in fact, not asking Reimu to strip naked. Sure, there's the 脱 that means strip, but the whole phrase "人肌脱い" (which literally means something like "take off your skin") is figurative for lending a helping hand.
No idea of the context though. Maybe it's like taking off your gloves? 🤔 Taking off your outer layer to help others sincerely?
