The second box is bigger and contains all of the rest of why I enjoy spending time with someone: s/he makes me laugh, we share common ideals, I feel safe and that I can continue to grow and change with that person, when I want to share a joy or sadness it is that person that I think of, when I have some spare time it is that person with whom I most often want to spend it. You get the idea.
Maybe there is even a small third box of all of the rest of things, stuff like being able to accept the little idiosyncrasies of the person, that I enjoy being seen together in public, that our taste in decor is compatible.
I personally want all three boxes to be in place...and I seem really good at getting two boxes full only to at last discover that the third box is mostly empty or missing altogether. Sometimes, I admit, I know that one box is not compatible but I proceed anyway, telling myself that it is okay to just have a couple of boxes and to go after that.
Others tell me that my expectations of the second box are too idealistic anyway and that what I describe as friendship is only intended for a relationship like marriage. Maybe I am trying to squeeze the contents of box number one out of box number two.
Or perhaps I do expect too much out of friendship.