piece , a model of menacing atmosphere 
(ROOT (NP (NP (NN piece)) (, ,) (NP (NP (DT a) (NN model)) (PP (IN of) (NP (JJ menacing) (NN atmosphere))))))
(ROOT (NP (NP (NN )) (, ) (NP (NP (DT ) (NN )) (PP (IN ) (NP (JJ ) (NN ))))))