Amelia entered the Fleurrh City Rookie Class Pokémon Showcase, hoping to win her third and final Princess Key so she could compete for the title of Kalos Queen in the Master Class tournament.
After gathering the highest number of Rhyhorn during the Theme Performance, she was declared the winner of her group and was allowed to advance to the Freestyle Performance. There, she delivered a performance along with her Shiny Dragonair and Espeon, dazzling the crowd. However, when the audience was asked to vote for the act they appreciated the most, a majority voted for Serena. As a result, Amelia lost the competition.
When she was leaving the Showcase theater, she approached Palermo and told her that she had performed better than Serena, but Palermo reminded her that she lost as the audience members had a different opinion. She then told Palermo she wanted to surpass Aria, and Palermo said complaining about the results of the Showcase isn't the best thing to do and that it is up to Amelia to improve herself.

Bulbapedia
Amelia (Japanese
アメリア Amelia) is a character of the day in the Pokémon anime who appeared in Master Class Choices!. She is a Pokémon Performer who comes from a notorious family. She is well-known among residents of her hometown, Fleurrh City.