A checkpoint halts you until you are allowed through. Dream tradition reads it as an obstacle or a test of permission, and as the feeling of needing approval before moving on.
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.