just a "stretch out" or real growing?

I’ve read a lot about stretching.

Does length gains due to PE mean:

… stretching or pulling a part of the penis that has been always there “out of the body” ?
… the body reacts to the stress and builds up new cells?
… something of both?

greets

estatic

Both to some extent with the emphasis on new cell and tissue growth. I’ve gained over 3”, I really don’t feel like I’ve just exposed more shaft that was hidden within me.