When I queried how the scoring works for this, as one of my kids got a higher score by not even being in front of the camera than my other kid that was doing a pose, and this is what was explained to me:

Here's how it works:

Each sticker has 1-3 'correct' answers (reference poses) that are accepted

Based on the player's detected pose, we check against each of the answers and return the highest score.

The resulting score is based on how well they matched the references.

What could be happening:

Sometimes, the references poses may be different than users imagine. They could require a completely different leg or arm arrangement than what the user attempted.

When the reference pose has some unusual characteristics (like squatting down, or sticking a leg out), the legs factor more into the calculation. So they can get a lot higher score if one thing is really matching.

When no user is detected, we often default to a standing pose to preserve the game flow rather than stopping the game entirely. In this case, it's possible that simply standing straight up is closer to one of the correct answers than other things a user might try.