This one can be done with a Manila folder or a mask.
1) Ask the client to create the outside as the outside of them and what others see.
2) Have the client create the inside to be what is inside of them. What they see of themselves and their thoughts, feelings, etc.
This leads to a great discussion and art activity on what is different on the outside and inside of us. It helps to get out the internal things that clients may want to share or be guarded about and helps them to self reflect on what they are showing of themselves to those around them.