In "1984", why does Winston find the obese, hardened woman of fifty, who is hanging clothes behind the antique shop, beautiful?

Seeing her as beautiful, Winston was committing an act of rebellion, in a way.  The "approved" definition of beauty, according to the Thought Police, would probably mean that this woman would not be beautiful.  Yet, she was natural.  She was what she was, rather than what she was t"told" to be by the society.  She herself was rebelling, or so Winston thought.  You might say "Ugly is Beautiful." 

Winston was appreciating the obese woman, not for her physical appreance, but for her noncomformity.  Interesting thought: Did the world of 1984 have supermodels?  In our day and age, this is the "acceptable" appearance for a woman, which many women try to conform to.  Orwell was perhaps presaging the intense focus on the "importance" of physical appearance as a means of being "acceptable."