How do you react to gory images (see details)?

Normally when I run across an image of a terrible injury online, I get this awful feeling in the pit of my stomach and have to click away. But just now I saw a bloody photo of a man with his spine exposed and it didn’t bother me at all. Here’s the difference: I had read prior to viewing that the “injury” was actually sophisticated makeup. It looked real, but knowing this information completely removed my reaction. Does this mean that my reaction to gore is really an empathetic feeling regarding the pictured person being in pain or something? Have you had the opportunity to test your reactions in a similar way, and what were the results? If you want, I can link to the makeup job image, but know that it’s pretty gross.