Headquarters stands for the centre of command, where decisions are made. Being summoned there is read as facing authority; working there as being close to power in your own life.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.