What does "peek through" mean?
In general, to "peek" means to look at something quickly or to only look at a small part of something. The verb "peek" is often used to describe the way that sunlight goes through small cracks and openings without fully shining through, as though it is looking through only a small part. So to "peek through" in this case means to "go through" in a way that small and limited because only a part of it is able to get through. Ex: The sunlight is peeking through the window shades.