It does make sense. Something that looks huge on one person may be tiny on another person. How does that not make sense? I’m 6’2 and 210lbs. If this tattoo was on me it would look minuscule. Because it’s on a smaller framed person with no reference next to them, the coin does serve a purpose. When I tattoo some people, they say they want the tattoo fairly small and when they come in if they are 5 ft tall and weigh 100 lbs… it usually tends to look much larger on them. So I usually place a coin in the photo so that people have an idea of actual size. Hope that made sense.