I got this as an anonymous gift for a 6 year old needy child for Christmas. She is beautiful!!! Her tail is way cooler in person, where the photo doesn't do it any justice. You press the button on her necklace and her tail flashes with swirlies and flowers in blue and pink lights. The lights blink in a pattern, and sometimes stay still.
My only slight issue is that the button on the doll I received was a bit stiff to activate. I was at first worried that it was broken, but once I got it to work, the button got easier to use. My own 6 and 3 year old girls fell in love with this Barbie mermaid. (I was informed that she is WAY better than their "boring" mermaid Barbies. Kids, I tell ya!)
I love that you can take this Barbie in the water; I bet she looks even prettier like that. Would have loved to have this as a bath toy as a girl!