It is about the past, the present and mostly, about the future. The presenting couples, or the team, does all the presenting. They tell about their lives, their problems, their success in healing their marriages. They are not counselors. They do not ask you questions about your life. You and your wife speak to each other, separate and away from all the other people. This is not counseling. It is not group therapy. You and your wife do all the "work" on your own. But you all come together to hear the presentations from the presenting couples.
As Mountaintop and TBL say, it is the experience. It is a process that they bring you through. It is not the same as marital counseling. Many people do Retrovaille, and then still go to MC afterwards. Check the website, www.helpourmarriage.org for more information. Particularly look at the page on the 4 Stages of Marriage. This is something you can show your wife. Ask her to go there with you.