Just like with Vanellope, Naveen's card has a more transparent look to it so that the card really stands apart from any of the characters with standard art
So, although you can play her on turn one, you'll still have to wait a turn to have her sing a song
Because once he is played, you take all of those lost and discarded characters and shuffle them back into your deck, no matter their cost or how long ago they were discarded
So it makes the most sense to hold onto Prince Naveen until you do have a song you want to play, but with the right deck combination, you shouldn't be waiting for long
However, it could also be due to her ability
It's a sweet nod to Vanellope's time spent with the Disney princesses in the second Wreck-It Ralph film