Could those be the Elements of Harmony? If so then based on the coloration of the gems they possess Celestia seems to have magic(magenta) on her crown and laughter(blue), honesty(orange), and Loyalty(red). Luna seems to have Generousity(purple) and Kindness(pink). So
Laughter(source of troll moments)
Kindness(oddly two of them)
Note I kinda guessed with Celestia having loyaty(red) since the shining of it makes it difficult to make it out as red or pink but since Luna's necklace obviously has pink Loyalty is the only elemnt unaccounted for and Celestia's necklace is the only one with a black space for that one.