I mean It is just kelp, a item with no magical properties. I'm actually surprised it's instant tho.
Now if it were a potion, or a spell, then yeah like in the little mermaid Ursula's Cauldron or Triton's Trident, casts the transformation.
But Kelp, I guess, Maybe they could have done something, like the sim collapsing to the ground and getting a stunned/uncomfortable/sick moodlet as their biology is reconstructed, maybe like a small gust of wind, or little water animation that swirls around the sim, but in truth that's all I would have expected.
Hopefully this means they splurged on the Realm of Magic GP... as they should've.
