Are people too easily offended by this? Absolutely. After all, the top half of the image is no more risqué than many covers on modern fashion magazine.
If I were a K-12 teacher, I wouldn't even use a model from a magazine at the grocery store checkout. Doing so would suggest that I endorse the look of the model, as an authority figure, which I don't. The model's look is is usually the latest lame culture fad. This affects young girls more than you know, so why even bring that shit to the classroom when there are zillions of easily available appropriate alternatives.