What was the purpose of Theresienstadt that set it apart from other camps?

Part of Theresienstadt was an 'ordinary' concentration camp and a Gestapo prison (mainly for Czechs), and another part was a transit camp for 'prominent' German Jews. It was for a time a 'model concentration camp' that Germany could should off to the Red Cross. To some extent, the Jews there were allowed to organize their own lives. However, the grim reality was that prisoners were regularly sent by train to Auschwitz.