Right now in Australian stores, when we buy chocolate we are presented with a choice in brands, but also a choice in how the product is made. Chocolate bearing the "Fair Trade" label come with the guarantee that the products of the product are made by farmers who are properly compensation and aren't the product of child label. As a facetious quip, when eating chocolate sans label, I remark "tastes like the sweat and blood of child slaves". It doesn't stop me eating and enjoying it, in fact it's the last thing on my mind when choosing and eating chocolate. What I care about are price, flavour, and the absence of milk.
It's not that I don't care about slavery, and in particular exploitation, it's just that in my role in the process as a consumer those don't factor into it. Even when I consciously think about it, it's a very academic exercise. The desire to have chocolate, money considerations, health factors, etc. Against those very real factors, the potential suffering is little more than an abstract concept.
I think that if I saw video footage of how the chocolate is made, it would change my moral considerations. This is a recognition of the role that passions play in our reasoning. when I buy eggs now, I buy free range. But it's largely an academic choice, an ought with no emotive emphasis. Seeing videos of chickens in the conditions in which they laid the eggs I think would make the moral factor of the decision a lot higher.
So if meat advertisement were reflective of how the animal lived and died, I think it would make the choice to eat meat more in line with how we think morally. This is not to argue that eating meat is right or wrong but that the way we talk about the morality of eating meat is not represented in our decision making process. Until such time, I think the moral outrage that many feel over eating meat is not going to be in line with how people think. Not because they're unreflective carnivores indoctrinated into the acceptability of eating meat, but because the process is divorced from our moral reasoning.