It is an interesting question though in situations with "No Shirt Policies", at what point does technically wearing a shirt still count as wearing a shirt when it isn't doing its job at covering nudity? I have had this thought, especially for women where people are normally harshest with, but somehow excuse the flimsiest piece of cloth as long as it's technically covering the nipples. Like, either stop pretending we care about the policy or make a determination what it is we're trying to accomplish with it.
In reality, it's one of many things that isn't evenly enforced and often used as an excuse to censor other things in combination.