Child's reaction to what is in the trick-or-treat bag.  Happy?  Disappointed?  Confused?

Children sitting on the floor swapping candy.  This also happens with stockings at Christmas.

Child's reaction to the home made costume they were begging for / dreading.  Is it better/worse than they imagined?  Are they being admired/teased by other kids?

Child's reaction to Halloween party snacks that look like bugs, eyes, etc.

Child's reaction outside a house that has figues, flashing lights, etc.  We have a guy who does Halloween and Christmas displays with music on the radio - always a crowd of kids on Halloween and a parent with a portable radio.