Open Self - is things that someone can look at you and just know about you. You look at me and see that I'm a Blonde Haired overweight fellow.
Hidden Self - these are things that I know but you don't know, like I sing and I enjoy learning.
Blind self - things that you know about me that I don't know. Like that my beard looks funny, if you think so.
Unknown Self - Things that neither you or I know about me. Like what my future will hold or what my retirement mutual fund will render.
These boxes will move as we learn more about each other. Take the hidden self example for instance, once you know that I sing and I liked to learn; my hidden self box will shrink and my open self will expand.