Have a look at the trees in this picture I took yesterday.
It is quite hard to make out the shape of many individual branches, because there is a hill blocking the sky’s light behind the trees.
Natural navigation often depends on being able to read the shape of the branches and this is easiest when we can see them silhouetted against a light background. It is hardest when they are far away and have a dark backdrop. Anything that helps us get from the latter conditions to nearer the former conditions is welcome.
Now try looking at the reflection of the trees in the water. See how you can now make out more detail about the shape of many of the higher branches. By looking at the reflection you’ve magically transported yourself to a position where you can see the trees from a new, closer and lower vantage point. This in turn means you can see some of the branches silhouetted against the sky.
Not magic exactly, but helpful all the same.