As long as you're not seeing big footprints or cracks, I think that's normal. We can see little imperfections in our plaster (3M) at night too.

We have Pebble Sheen - we see the same thing with the lights on at night. It's like trying on swimsuits in the dressing room under the wrong lights. You feel pretty darn good about your body trying on swimsuits at home in your bathroom, and wearing your little bikini out to the pool/beach in the sun. Then you decide you want another swimsuit and you try them on at the store with those mean ol' flourescent lights, and you want to make a run for lipo pronto, even though you never even considered it before and hate any sort of pain!! Your pool is the same - the lights at night are not nice to all of the normal little hills and bumps. The overall look, I am sure, is beautiful.