It comes down to (1) A hole in the underwear. (2) Super low rise. (3) Not wearing anything. However...

Can't you just leave it up to the imagination? (don't say it out loud...)

So you're saying that if not observed, those states are in superposition...?

So they're superimposed at 33% transparency...?

When you have 33% as "not wearing panties" it's semi-transparent no matter how you slice it.

In other words, Chen's underwear is semi-transparent. (Logical conclusion.)