Bars on a window are read as restriction you can see past but not move through — a situation, rule or fear that limits you while the wider world stays in sight.
When this appeared in your dream, what were you feeling?
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.