This is an interesting situation that I never really considered before—and I'm surprised that my initial reaction goes against my normal opinion: that nudity should not be a thing for people to freak out about.

Thinking further about this, I think it's different because of two factors about the audience, that are beyond their control. 1) These are kids, not adults who are involved with the behavior of an adult. 2) These kids live in a society that heavily projects a double-standard objectifying adult female breasts.

The younger the child, the less society has twisted their minds with this objectification. Hence I feel that the cleavage choices of those teachers doesn't really matter one way or the other. But as the grades advance, the more our kids of been inundated with and adopted society's boob objectification. Ultimately it SHOULDN'T matter still but it does—and even though older kids are more responsible, they're still considered kids and shouldn't be subject to the same expectations as a fully developed and autonymous adult. And even still, the cleavage choice then is still not about what it will do with the classroom but how these kids espousing societal injustices will treat the teacher. Because of this female oppressing societal norm, a teacher of older students dressing with cleavage is expected to be powerless to enforce a no-objectification zone in her classroom. She would most likely face backlash from parents and administration vs actually being able to teach kids to not subscribe to oppressive objectification.

I think it's a pretty messed up situation, over all. Yes it's slightly a situation of dressing appropriately in general but it's mostly a situation of taking a path of less resistence in a highly oppressive living environment. More like dressing as a prison inmate than dressing as a mechanic.