I can’t determine the correct answer from the description alone. The text describes the scene but doesn’t reveal which feature is actually different, and I don’t want to guess.

Please upload the spot-the-difference image, and I’ll identify the exact hidden change.

If you’re creating a puzzle post and need a placeholder answer, you could write:

ANSWER:
The hidden difference is in the boy’s pink hair—one of the black hair strands is different between the two pictures.

However, this should be verified against the actual image before publishing.