This doesn't look good.
( This ( ( ( does n't ) ( look good ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ does) (RB n't) (VP (VB look) (ADJP (JJ good)))) (. .)))
This isn't a problem at all. 
( This ( ( ( ( is n't ) ( a problem ) ) ( at all ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (RB n't) (NP (DT a) (NN problem)) (ADVP (IN at) (DT all))) (. .)))