The penthouse sits at the very top, so dream books read it as success, status and a wide view of your life. Feeling isolated up there points to the distance that achievement can bring.
Where in your waking life have you met something like this lately?
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.