。
The little girl stuck her tongue out at him.
Literal
Young girl [topic-は] him [toward-に向かって] tongue [object-を] stuck-out.
~に向かって ('toward / facing') is a directional marker with more intentionality than plain へ or に — used when the action is deliberately aimed at a target. 舌をつき出す is 'stick out one's tongue.' つき出す is 突き + 出す = 'thrust + put out.'