A recent photo campaign is fighting sexism by tackling the problem at its root: men and hyper-masculinity. Jenny Francis and The Sun are putting "ordinary men" next to photo-shopped underwear models, to show just how ludicrous the common male ideal really is.
As demonstrated in the campaign, male models are muscular and poised. They command attention, and ultimately look powerful. This is in direct opposition to ads where female models look pretty and dainty. Men get muscles. Women get breasts and thinness. Men are supposed to do things with their muscles, and women are supposed to be looked at. Men are subjects, and women are objects.
This campaign, by presenting men who don't resemble Superman, disrupts assumptions that uphold men's power. The men's musculatures aren't defined like the models', and they don't command attention with the same authority. They don't live up to what a man is supposed to be. This is a direct threat to the patriarchal power structure. By asserting multiple definitions and images of what a "man" is, especially when those images don't resemble Adonis, the campaign asserts that men as a gender aren't all physical embodiments of power. This understanding of gender could also disrupt the system that grants men power on a social level.
Masculinity is strictly enforced, because it grants men power. Those to whom it gives power are expected to uphold it as a social construct. When men defy the rigid construct of masculinity their existence becomes a threat to sexism as a whole. If there is no unified group to seize power, there can be no oppression.