The question has already been answered, but to look at it a different way, the more muscle mass you have the more 'definition' you will have at a higher bodyfat percentage
I'm gonna use abs as an example. Someone who has a ton of muscle mass may have some thick, dense abs. Their abs may protrude noticeably at 12-15% BF. An average person with average muscle mass likely has fairly flat abs, so they may need to get to sub 10% and they still might not see that 'pop' of the abs that they want
Same idea for all bodyparts. But unless you are huge, the difference may be negligible