Our story here, if you can really even call it that, is nothing more then jumping around to various points in time, past, present, and even future, where we see Batman, Superman, and Wonder Woman discussing the Justice League. The story is narrated, in part, by each of the three. Really not much to it in one sense, but it is still a tremendously well done character study on the big three and their friendship to each other. At one point Diana narrates this "There's only one problem when three friends get together....someone always gets left out." I found that particularly interesting in context of one of the last scenes, where the three are getting together in the present.
Each one feels like the odd man (or woman) left out. I had never really though of that before this issue. But really it makes perfect sense. Bruce would feel different from the other two being the one without powers, especially given how powerful the other two are. Clark would feel left out because Bruce and Diana are far more natural warriors then he is. And Diana, well it's easy to say she would feel left out being the woman of the group, and I'm sure that's part of it, but also Diana wasn't raised in "man's world" like the other two. I have no doubt that even after all the time she has spent outside of Themyscira she still feels a tremendous culture shock.
As I said before, while this issue doesn't do much to move forward any story going on at DC at the time, it is a great character study and anyone who is a fan of any of these three characters should check it out.