Due enough surface of her big boobs,nipples are hidden till their edge under black leather and white band on the part we see as top,that part looks short,but have more surface than we can see from our point front-below,same as a cube seen from front-below we cannot see his roof side due the angle.
The major part we see of her boobs are the below side,not the front. Try to see her boobs as a pair of eye-baloons,nipples as eye-iris and the clothes as eyelides,if these eyes send their irises to the top of the eyebaloon,eyelides can cover them and make it appear as full-white eyes.
Some parts of human body can be comparissed with simple forms,and their flexibility can allow lot of curious effects. This is a example. I love draw curious effects caused by displacements,turns and torsions,rather than usual or conventional appearances. They help show human body more alive,and more funny or humorous too
However I dislike comments which looks like only be focused in find mistakes or so. But in your case,I think is a fair question. Hope I would not be wrong about this.
nah, it was a legitimate question. it just seemed really weird when looking at it here and the colored version. I must just be reading the depth of the image wrong in that case, haha. thanks for the explanation!