Tom Noonan did not receive an Oscar nomination for portraying Sammy Barnathan in Synecdoche, New York.
Of course what Tom Noonan does here is very specific, and an essential facet of the film in that his Sammy is the double of Caden in more ways than he plays him. Obviously Noonan looks, really, nothing like Philip Seymour Hoffman. That is not the point and Noonan's performance hones in on this idea of a different kind of a representation of Caden. In that Caden is an observer rather than an actor in life, therefore it is a most curious thing for an actor to play this observer, while being an observer. That's is a strange idea to be sure, however it makes this a particularly fascinating performance to watch as Noonan realizes this act in his own way that is something rather clever. Caden is of course troubled by this state which Noonan contrasts so effectively by portraying a man in a state of calm in his own observation process. Noonan initially portrays that, despite this life, Sammy wants for nothing in his own existence of acting as the observer of the observer who is troubled by being the observer. Noonan exudes a calm in this place of strict connection, which he plays with in such an interesting way. In that he directly acts a certain moment will present the needed intensity of emotion to be Caden, yet can calmly be himself the next moment, such as so genuinely commenting on the talent of Caden's wife who is an actress.
Noonan's work here is entertaining in itself, in that his exact state is humorous to be sure, but what is so special about it is how well he finds this strange state of the man who is almost a comforting factor in the film by showing a path of the observer initially. The idea though becomes that in a way Sammy is less an observer because he is at least acting out Caden's observations unlike Caden who is simply still watching them. This does not change until Sammy's action to take action where Caden did not which in turn finally leads Caden to take action, the action Sammy had taken, how that somehow adds up is why I love the film. Noonan's work ends up being quite something even more than this curious side show though in the end, as Sammy's observation of Caden's action leads to something more. Noonan is heartbreaking quite frankly in finally attaching the emotion of the performance to Sammy finally observing by removing that initial calm in this moment of observation. This leads to a performance of Sammy, a tragic performance, which is emotionally charged as it should be to represent Caden, yet with this calm as Sammy takes his own action in the performance. It is an utterly bizarre end to the character that Noonan delivers in such a powerful way by naturally reaching this breaking point as the observer becomes the true actor in the end.