Cashier cheating?

I got this from failblog.org

The issue here is does is this considered as a fraud? Because ultimately, she is overcharging the customers using her own body (breast), assuming she does it on purpose without being told to and she does not receive any sort of gain by doing so. By right what she is doing is wrong but since she is not getting anything in return, what will she be charged in? Fraudulent? But remember she does not receive any gains/benefits

On the other hand, assuming she does it unknowingly, does not gain any sort of gain/benefits, what will the verdict be? There is a saying in Chinese, "Bu Zhi Zhe Bu Jui", meaning if you are innocent if you don't know or you are innocent if its an accident. But then again, if we rely on all these kind of saying, killing spree will happen as there is another saying which is an eye for an eye. Sometimes law is fair, other times its just law, with no flexibility. But I wonder, in this case, will it differ? Or she will be charged but with a lighter sentence.