I think it's possible but in the extreme sense. Yes, it's a real thing that people do; snipping nipples. It basically works like a nipple piercing and it makes the area more sensitive. It's for truly masochistic people though, can be pleasurable for them.
It can also be compared to how clamps work.
Snipping the skin?? Yikesss
That sounds a quick recipe for an infection
Especially with those prison nail clippers, ouch
What did they do to his nipples? I know that they stimulate it. But how and is that really possible in real life?