Since everyone's talking about how Sapphira could have done more with the vampire concept, here's a fantasy reveal sequence to take those fangs further.

She walks into the stage wearing a black gown, with no hint of blue whatsoever.

At the start of the song, she shows her fangs like she did.

She continues the lipsync with no tricks, being ever so patient, just some campy vampire dancing.

Towards the end of the first chorus, "and take off all my clothes", she starts tearing away the gown timing perfectly the very end of the chorus, "padam padam when your heart goes padam padam", with a reveal into a skimpy white vampiric bodysuit. From black to white, still no blue.

She continues to dance this time with higher energy. At some point in verse 2, "wanna see what's underneath that t-shirt", she flips her hair and does a wig reveal.

The crowd gets wild, she dances campier and campier.

Then, at the end of verse 2, "cause i can hear your heart beating," she takes out a heart from her breast plate, bites into it, and instead of red blood covering her white gown, it's her signature color blue!

The crowd gets wilder. This time she has everyone's attention as Nymphia is out of tricks doing her reveals early.

She works the crowd, continues to dance silly, and with the final "when your heart goes, padam," ends with her gliding split.

Don't know how to pull this off logistically and mechanically with the dress. Hire an engineer for that.