Melody has fun with her belly button

Has anyone seen this movie? Did you notice that when Melody becomes a mermaid, when she is about to sing her song, she floats backwars on the surface and her belly button seems to move alot over her belly! Her tail remains underwater and you mainly see her from belly to head! But what really gets my atention is that the way she moves affects her belly buttpn's movement! Really! Her bellyb utton moves up and down, under her shirt and then down to the middle, then back! Also there are the parts where her belly goes halfway underwater, letting water travel across it, but her belly button just remains visible!

Melody seems to have alot of fun here showing off her bellybutton to the sky. Its like she is thinking: "Hey world! Im a mermaid now! Look at how I can show my belly button now! " And this is also like the first time her belly button shows (at least that I can remember).