I agree, sure, that would be more accurate. What I see is a tight stiff surface and it is all much smaller, getting closer to the body. I referred to "testicles" but I guess you're right, it's really the scrotum, and the testicles are inside and I can't see them, so I can't say if they get smaller or not.
Never do I notice this phenomenon when outside of POIS, I check regularly (basically every time I pee). This happens only during POIS, from time to time.