The Nudity concept as we see today wasn’t the same in that era. In Kerala, untill 1900s, most of ladies including those in upper Hindu castes never worn blouses. Most of them were bare chested like men. There was no social shame in exposing the upper body for anyone, be it upper caste or lower caste.
The breast tax was supposedly forced by the landowning king on lower caste Hindu women, which was to be paid if they wanted to cover their breasts and was further assessed in proportion to the size of their breasts.
Typical dressing pattern of Upper caste Nairs and Lower caste Ezhavas in 18th century. Both Nair and Ezhava ladies never wore blouse. Nair Ladies may wear more ornaments while Ezhavas may wear a shawl to cover the upper body when they feel so. Being barechested is a common thing in that era.
The climatic conditions makes it hard for people to cover their bodies with clothing and they never saw breasts as some sort of sexual organ. Its just a normal thing just like how men have nipples. Both men and women of almost all Hindu castes worn just Mundu (Dhoti) while being bare-chested most of the time.
The only group who covers their breasts in Kerala were those who belong to Muslim, Jew and Christian faith. Muslim ladies worn a long loose jacket called Kuppayam (Jacket in Malayalam) while Christian ladies worn a tighter version of it, called Chatta.
But the brave village woman Nangeli is about a woman who lived in the early 19th century at Cherthala in the erstwhile princely state of Travancore in India and supposedly, cut off her breasts in an effort to protest against the caste-based breast tax.
The village officer of Travancore, came to her home to survey her breasts and collect the breast tax. Nangeli revolted against the harassment; cutting off her breasts and presenting them to him in a plantain leaf.
She died soon from loss of blood. Following the death of Nangeli, a series of people's movements were set off. Soon the place she lived had come to be called as Mulachiparambu (meaning place of the breasted woman)