An artisitic presentation wherein passersby showcase their testicles against the outside of a framed exterior window pane for patrons dining in an exquisite restaurant to view, leaving an opaque film, similar to a fingerprint, for all to see.
(culprits) "Hey, let's go leave a bohemian nut gallery for the rich a**holes in that restaurant we got kicked out of last week."
(rich a**hole) "Honey! What is that smudge on the window?"
"Mother of God... that's a bohemian nut gallery!"