I think that the message of the film is one that speaks out against the atrocities of the Holocaust.  The ending scene of the gas chamber door, panning backwards, is designed to remind the viewer of the horror in the Holocaust.  The film's moral is one that stresses that anything even remotely close to the Holocaust is something that must stop and must be prevented at all costs.  Bruno's establishment of friendship with Shmuel and the sacrifices he makes in the name of friendship lead to his own death.  The film reminds the viewer of how the Holocaust was a time period in which transcendent values like friendship were sacrificed on the floor of the gas chamber or in the dirt of "Out- With."  In doing so, the film reminds the viewer that the need to understand the lessons out of the Holocaust are vital.  It is for this reason that Bruno's experience becomes so important.  The message is clear in its repudiation of the Holocaust.  The moral is one in which one learns to stand up against the Holocaust because of its intrinsic horror and lack of regard for human life.