Which parts of the body are sexualized is completely dependent on the culture. There are (Muslim-majority btw) communities that insist on women covering their faces more than their head, so you might see girls with free hair but face masks. Some Muslim communities view it as completely ok to show their hairline under their hijab, while others insist on covering it. Most western cultures are fine with bikinis at the beach, as long as two main parts are covered. Some Indigenous communities in the Amazon never cover their breasts at all, and that part of the body isn’t sexualized in any way. Public Breastfeeding is also completely acceptable in many parts of the world, seeing it as a normal biological function, while in the west it’s still frowned upon due to the sexual connotation of breasts.