Why is Ethan looked upon as different?
The main character of Ethan in Edith Wharton's Ethan Frome is a man whose life has been miserable since a very young age. This is why, through time, he seems to have developed a sense of tragedy that is compensated by his kindness to people and his ability to love others.
We know that Ethan seldom experiences victory of any form. At one brief point in his life he attempts to go to college, study engineering, and turn his life around. However, the lack of money seems to always be a factor in Ethan's family and he is unable to attend.
We also know that Ethan's mother is a sickly woman of whom Zeena took care dutifully. It is precisely that sense of duty what prompts Ethan to thank Zeena by proposing marriage. Less than a year into the marriage Zeena turns intolerable. She stops communicating with Ethan, leaving a thick feeling of tension in the household. The thickness of the atmosphere, combined with the wonder of what is going through Zeena's head, is enough to drive anyone crazy.
Yet, it is precisely this consistent contact with misery that makes Ethan different. People are aware of his sad life, and people know that he is a naturally-kind person. He is described as someone who is:
"aware of the huge cloudy meanings behind the daily face of things"
Now, keep in mind that he is mostly looked upon as different because of the gross deformity of his body contrasting with the candor of his personality. We do not hear of Ethan being any different than anyone else prior to his horrid accident, or before he married Zeena.