A scaffoldong material which is strong but flexible is placed under the mouse skin which then grow over the scaffold. The material that is used for the scaffold is very sticky for cells of the body, so they like to attach to it and grow blood vessels and al the other cells neede to make a human ear. These are then transplanted onto people when they have lost theirs ears due to an accident or disease.
It’s also not a real ear, it’s basically just cartillage tissue that looks like an ear. The cells grow into an ear-shaped mould.
I have to say that I understand the reason behind this type of thing (e.g. the ear transplants as Tim mentioned)
but looking at the images still makes my stomach turn. I don’t know how I can really describe it but when I first saw that picture, something inside me told me that it was just wrong, and I still feel that way now.