I don't mean to sound like an Old Fart, but the 1957 Carnival just seems to me so much more charming and weird and ingenious--look at those bipedal seahorses with the mermaid--than the current version, which seems to be about nothing more than bare flesh. Maybe the 2015 videographer simply did not film the weird costumes--but then again, every other video of the 2015 carnival on YouTube features the exact same stuff. Now, I like bare flesh as much as the next voyeur, but I would really prefer to see a papier-mache Godzilla any day.
This page semi-coherently explains: "...a ceremony in the Newar community in Nepal in which pre-adolescent girls are 'married' to the bel fruit (wood apple), which is a symbol of the god Vishnu, ensuring that the girl becomes and remains fertile. It is believed that if the girl's husband dies later in her life, she is not considered a widow because she is married to Vishnu, and so already has a husband that is believed to be still alive."