''Could someone please provide an example of this?''

The way to adapt to the behaviour of the ValueModel used in the ModelViewController (and 
ModelViewPresenter in DolphinSmalltalk). 
Say, you have a Person class with two accessors:

  Person>>name
    ^ name.
  Person>>name: aString
    name := aString.

The pair of accessors (name/name:) is called an ''aspect''. You can treat an aspect as a 
ValueModel, passing it to UI elements expecting ValueModel. In MVP:

  |person adaptor|

  person := Person new.

  adaptor := person aspectValue: #name.

  adaptor value: 'Mister One'.

  Text''''''Presenter showOn: adaptor.