It could cause people to take action around laws or other issues that contribute to gun violence - because they want less of it to occur.
For example, genocide in Sudan was pretty heavily covered, including some graphic content. Yet we didn't do much of anything to fix it. There were not many people saying "send me over there so I can stop it".
Most people always want someone else to fix the issue for them rather than take direct action themselves. We know that socioeconomic issues are the main drivers of gun violence and violence in general. Most people are not willing to address those issues through paying higher taxes (it's always tax some other person), volunteering, or even being neighborly. Many of the better off people do not live in the areas affected most by gun violence.