at the dinner table

The little toddler, barely two years of age, sat on her high chair furrowing in her mum's bag. It was becoming a long meal, as often the case when copious glasses of wine are involved. She brandished out an unused nappy and with great concentration began unwrapping it. One by one, the voices on the table die down as all eyes turn to the nappy on the dinner table. For a few split seconds, there are only expressions of concern, but soon a dozen smiles emerge like a Mexican wave as it becomes obvious that the nappy is, in fact, not used. The toddler stops playing with the sticky tab and gives the rest of the table a proud grin. A few chuckles break before everyone erupts into roaring laughter. She laughs along, but soon detects a sense of alienation, which she does not like. Her little lips purse together and begin to quiver as her face turns bright red. Suspense builds as the laughter subsides. The dramatic finale is finally delivered when the toddler bursts into a howling fit of tears.

I am left stunned: how is it that this little fluffy haired two year old knows the difference between "laughing with you" and "laughing at you" while I still falter at such subtleties?