The original picture is advertising intended to make a point. Advertising is known for pushing boundaries, and exaggerating things. Why? Because advertising is increasingly ignored due to desensitization; we are burdened with hundreds of advertising images every day.
A comparison between a novelty toy and an automatic weapon is obviously unnecessary because many things are dangerous without being that dangerous. But the advertiser obviously chose that because of current affairs. It gets noticed and that's the whole point.
The goal of the advertiser is to get people to notice. It does not necessarily have anything to do with gun control, but it's riding the coattails of that issue to become noticed.
If people are objecting to the image simply because it's a hot political issue, then I would tell them to deal with it, lest they want to go down the censorship road.
Edit:
To better address the question of whether the image should be kept or removed: If it properly shows evidence of a claim (the source of the question) it should be kept. I would remove it if:
- It did not show evidence of the claim, or
- Was not original material from the company making said claim
In other words, if the image was a second-generation, or third-party image made by someone other than the company or individual making the claim, it could potentially misrepresent the claim or impart a different meaning than the original owner intended.
If this candy vs. gun image is from the source of the claim, then it is best suited to represent the claim in dispute.