The weight of the fabric, the style of the pattern, the size of the bustline, the style of the waistline and the undergarments all affect how a top/blouse looks upon a woman. This blouse has a nipped-in or tucked-in waist so you cannot expect it to hang straight down which would thus less emphasize the bustline. Also, if a top/blouse is tucked into the skirt (as opposed to hanging over it), the bustline is more emphasized. However, the point of drape is still the bustline.
The size of the blouse is determined by the size of the bustline. That size, in turn, determines how wide to make the neckline and armholes and how far from the neckline the armholes should be. Example: If I were to wear a top one or two sizes larger than my size, the neckline would gape open in the front and not lay against my chest (unless it was a turtleneck) and the sleeve seams would hang down the upper part of my arm, giving me a baglady look and also allowing curious eyes to peer down my blouse when I bent forward or was lower than the onlooker, such as when genuflecting.
Women who are amply endowed need supportive undergarments or else they suffer from back problems. These supportive undergarments must be constructed in such a way as to support the weight being held and therefore they give shape which you simply cannot avoid except by layering your clothes (a sweater draped over your top or blouse) which is impractical and dangerous to your health in a warm or hot climate and often does not solve the problem.
Sports undergarments suppress the bustline to a degree but are also unhealthy for daily wear, especially by women who are of childbearing age because they are made of elastic and suppress the delicate tissues and structures needed for nursing.
Women these days have a very hard time finding proper tops. Skirts and tops are made out of scraps of fabric that are so small that I used to throw them away as useless after making a garment for myself. I can walk the malls and Goodwill for hours at a time and find absolutely nothing appropriate and I am anything but well endowed. The fabric is sheer, a lot of tops are made with Spandex (elastic) to make it cling tighter to the body, the necklines are plunging (they need to make a new size called "Implants"), and the colors and patterns on the fabric are way too loud for daily wear, much less appropriate for church. Sometimes the higher-end manufacturers make more decent clothing but it is expensive unless you find it in a thrift shop.
Clothes are made for those with money -- the 20s, 30s, not mothers of large families or women in their 40s and over. The young people want to show off their bodies. Manufacturers comply. And yes, it has been getting worse and worse since the 50s and 60s. Everyone wanted to look like Monroe. Every man wanted every woman to look like Monroe. Then there were the hippies who no one but other hippies understood what they wanted to look like. You tended not to see their bustline for all the vests and hanging, tangled long hair covering the front of their chest, not to mention the guitar.
The best solution is to learn how to sew and how to alter a pattern to allow for extra fabric where needed and live in a cold climate where you can layer your clothes. The same applies to skirts. Women are at the mercy of the manufacturers and we are in a sin-ridden world.
And in case no one has noticed, it seems to me that men's slacks are becoming tighter as well. I am shocked at times at what I see. Sex sells. Modesty doesn't.