How does Ulthera work to improve the skin's appearance?

A new machine called Ulthera intensifies sound, makes it shrill enough that neither humans nor dogs can hear it, and focuses it in a precise location under the skin. There, it vibrates molecules releasing energy and heat. Those of us old enough to remember Ella Fitzgerald's Memorex commercial from the 1970s know that sound has enough energy to break glass. This energy can be harnessed to kill fat and shrink the skin and prod it to make new collagen. After a few months, the skin looks tighter and thicker with less unwanted fat.