Daily tease

Always on cue

Every move you make, this companion mirrors. There is no catching it, yet it keeps perfect pace.

The question

I follow you all the time and copy your every move, but you can’t touch me or catch me. What am I?

The answer appears with light and disappears when the light is gone. It needs you as much as you need a light source.

Your shadow. It lives wherever light and your body meet, stretching as you stretch and vanishing when the light slips away.