The Marriage was a replica of an ancient Flemish painting by the master painter Van Eyck  

It was installed in the shop window for the  
1995 Melbourne International Festival of the Arts. 

What was so unusual about that?
Parts of the painting were alive. 
The creator of the piece placed his face and arm in the painting.... for 2 hours a day. and then replaced his face and arm with that of an exact replica when he left.
And then on another day, there were two actors present,
the wife and the husband.... 
and sometimes the dogs tail just wagged gaily at the audience.