There is a big black market for iPhones and most electronics in Brazil due to their tariffs. There are plenty of articles on the internet of flight attendants and others who were arrested for smuggling.
Foz do Iguaçu is on the border of Brazil and touches Paraguay and Argentina. She was likely smuggling the phones. As for her death, body (likely) reacted adversely to the glue holding the phones to her body.
She got greedy.
Should have played it safe and only glued 25 phones to her body.
One phone over the line, sweet Jesus, one phone over the line.
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Reminds me of the Ellen Degeneres bit back when she just started out and was actually funny:
Pretending to be in airplane seat: Stewardess says all seat is fully upright position. She leans back 3 inches and says, “Dead.” Leans back forward 3” and says “Alive.” Then does it a couple more times.