Priscilla and Valerie committed a violation of the voting out procedure prior to nomination night. House rule #9 states that no one is allowed to discuss nominations outside the confession room, directly or implied. Because of this, Priscilla and Valerie were the first two nominated housemates for eviction.
Priscilla and Valerie talked about the nomination process days before the nomination and thus they were automatically nominated.
Photo courtesy of Pinoy Big Brother official website.