Well, based on the unrendered side view, I would say it's because the boobs look broken. Notice how they protrude beyond the dress, and how they look hacked off at the bottom?

When enlarging the breasts you have to use a combination of the breast dials so that they don't end up looking like that.

Once you get the breasts properly enlarged, then you need to also enlarge the breast part of the dress as well.

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi