From the Experiential Tools website:

"The use of metaphoric objects enhance reflection and dialogue by allowing learners to attach their thoughts to a tangible object that can be touched and shown to a group. When participants talk or write about the object rather than about themselves directly, they sometimes express thoughts that would otherwise be left unsaid. Often the thoughts, ideas, and connections inspired by the objects lead to broader and deeper reflection sessions than when using dialogue alone.

• Recent research on the brain and learning suggests that when learners can attach thoughts/key concepts to a metaphor they may retain it longer.
• Often people find it easier to share when they can attach their thoughts to an object or image.
• Conversation and reflection can become more metaphorically rich than with conversation alone.
• This method is “student or participant centered”. It puts more control on the student/learner for interpreting their experience/feelings/goals rather than the teacher or group leader directing and possibly inserting their own interpretation or agenda. This allows for spontaneity in reflective discussions and possibly a deeper connection to the learning experience or academic material."