Co-created by Richard Bandler and John Grinder, the NLP Milton model is something of a contrast to the Meta Model of Neuro-linguistic Programming.
The NLP Milton model is based on the work of pioneering hypnotherapist Milton H. Erickson. Bandler and Grinder met with Erickson regularly to model his techniques, and published two books, "Patterns of the Hypnotic Techniques of Milton H. Erickson Volume I" (1975) and "Patterns of the Hypnotic Techniques of Milton H. Erickson Volume II" (1977).
Unlike the Meta Model, the NLP Milton Model uses deliberately vague language in order to help a client reach into the depths of his unconscious mind. When your thoughts are strictly on a conscious level, they are restricted by explicit language patterns - the conscious mind tends to distort the facts, modify or delete key aspects of the experience, resulting in the exclusion of vital aspects of the issue and important concepts of the experience.
The theory is that by using statements that are more open in nature, including the use of metaphors, you leave room for thought for the client, who can then fill in appropriate details in the present gaps using their unconscious mind.
This allows the skilled therapist to follow and understand the reality as perceived by the client in order to build a genuine rapport or portrait of the event. With this understanding, the therapist is much more able to help the client effect change.