A portioned booth where one can intereact with another person anonymously, with a barrier in between. No physical contact occurs.
A booth or viewing area in an adult establishment, mainly an adult bookstore or video rental store, where a person can inter react with another person in another booth.
There is no physical contact involved, and is more for the voyeur than anything else.
Generally they are glass portioned, with curtains. A signal device lets the other person know you are watching, and they can choose to allow you to view or not.
Sort of like Cam Shows on the Internet, where you can view a person masturbating, and give instructions on how they should proceed, for a fee.
Noteworthy: Based on the old time peep shows. You paid a nickel and watched a woman strip or masturbate.
There are also legal ramifications to take into account.