According to Lucy Calkins, the guru of guided reading (my thoughts), in her book, Building a Reading Life, she states that, the most important way to [build a culture that values literacy] is to make reading into a richly social activity.
In her book she also states, that we need to give them the conditions that we, ourselves, want as readers- and these include time, choice, companionship, and opportunities to grow.
Partner reading (or literature circles) and discussion provides that social activity; the companionship she mentions. The deeper thinking generated through the use of these cards, adds to the opportunities to grow.
During or after their reading, have them draw out one card at a time and follow what it says. Some cards ask them to reflect and share on their own reading, while other cards ask them to have their partner reflect and share.
When I teach how to read with a parter and have "responsible talk", I introduce these 12 cards. At times, I also use them in my guided reading groups to help generate high quality discussions.