is a kind of installation, i have practised a number of times:
at the end of a shaft or aisle closed off by a signal tape and inaccessible to the visitor, there is a very small monitor. the video is not exactly visible with the naked eye.
the visitor has the possibility to see the film in detail from the barrier with a provided binoculars and to hear the corresponding sound over headphones.
this form of presentation arouses some curiosity and requires initiative and concentration on video.
(ulrich phips fischer)