Anyone may do readings anyway they like, but the design of the RWS cards is not amorphous with respect to the intended meaning. The Minor cards illustrate the Book T titles. In this case, 6 of Cups = Sun in Scorpio = Pleasure. The guard cannot be walking away from personal pleasure, as he is not involved in the event depicted in the card. Obviously, he is merely refraining from poking his nose into the magic taking place between the two children. Of course, if a reader wishes to change the meaning intended by the author of a deck, that is their perfect right. My personal respect for the authors of the RWS may account for the fact that I would never consider using it merely as a prop for intuitive fortune-telling.
ETA. Anyhow, this forum is not primarily about fortune-telling. According to the Tarot History and Iconography description, it is officially the "Study of the symbolism and detail of the original Rider-Waite Tarot."