Yeah, it's a technique called "blood lining." It's usually used on tattoos that are more realistic because of the lack of a heavy black outline. The artist usually goes over the stencil placed on skin with water so, when the stencil eventually rubs off, the scratches that are left from the blood-lining, (like the ones in my photo on my fingers), can be followed instead.
There are many arguments I could make against that but I don't want to get into that. I eat meat. Meat is murder. I'll just go with that so I won't have to get into an online debate over a "tattoo" that was done out of fun.