Why do different sizes of implants look incredibly different on different women?

The same implant in a different patient may look different as their breasts are different in size and shape before the procedure. If you look at the pre op photographs you will notice that the patients will have breast that look different and have varying dimensions and volume. Great  question! 

Thank you for your question.  You are absolutely correct that many factors go into how a particular sized breast implant looks on a person.  The chest diameter, shoulder size, and most importantly breast width and base width all determine how a particular sized breast implant will look.That is why it is so important to have a formal consultation with a board certified plastic surgeon who will do measurements of your base breast with, and other breast measurements to determine the best size breast implant for your unique body shape.  There are many methods that are available to estimate the proper breast implant cc size to obtain a particular cup size following breast augmentation.  For more details on how to choose breast implant size please read the following link:

Yes, you hit the nail on the head. Implants often do look different on different peopel that is why it is difficult to tell people in these forums what the best implant for  them is.