A good rule of thumb is to always opt for the solution that avoids changing any code, especially if you don't understand that code.

By changing the code, you effectively broke the entire image system for all other images on the site. It would show up when you tried to add new products, and you would be wondering why it doesn't work, most likely forgetting completely that you changed the code earlier.

A simple image copy would have the effect of fixing your initial problem without breaking or changing anything else. That is the best solution.