Frosted glass lets light through but hides details, so dream books read it as partial clarity — knowing something is there without seeing it clearly, or privacy kept on purpose.
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.