Using objects to depict other objects
Pareidolia


  Pareidolia is the tendency to interpret a vague stimulus as something known to the observer, such as seeing shapes in clouds, seeing faces in inanimate objects or abstract patterns, or hearing hidden messages in music.
  source: Wikipedia


There are many examples on the internet beyond Arcimboldo, just look for Pareidolia in art.



Women Forming A Skull By Salvador Dali