this picture is so dumb. I don't know why people ever refer to it. The pictures for 3-4 percent and 6-7 percent are probably actually right at the same bodyfat level. Lighting, vascularity, filtering and posing are the differences between these two physiques, not bodyfat. and the 15 and 20 percent pictures look like they're pretty much the same level as each other as well.
Aside from all that though, the number is such an arbitrary thing. I have no idea what my bodyfat % is, and I don't care to find out. I'm lean and I look good. I don't have a % tattooed on my forehead for people to read. Train and diet until you have the physique you want. This will take however long it takes, and will be dependent entirely on your effort.