How can I tell if the shots were delivered accurately during Ulthera?

While looking around at dermatology procedures this morning,

It is said that Ulthera contains 2,400 shots per tip, so one person cannot use all of it; therefore, it is designed to be shared.

They say they disinfect it and reuse tips that others have used.

In that case, I am wondering how I can check if the shot I wanted went in.