I got a message that my score is being reviewed. What does this mean?

If you received that message, it just means the score you submitted falls within the range of scores potentially eligible for a trophy.

If you get a message that your score is under review from a score submitted for any of the challenges, that score may not count toward that challenge due to the time constraints in reviewing all of the scores. Your game score only applies toward your high score if it is one of your first three-game plays for the day for that game. If you have more than three gameplays and are in a challenge, your game score will only go toward the challenge and not the High Scores table or NP reward.