The live chickens were not actually dispensed. Instead, the machine produced coins with eggs on them, with numbers on the coin corresponding to the sort of conditions chickens were raised in. For example, the number 1 indicated free range, while the number 3 meant the chickens were kept in cages.
The video below shows the vending machine in action, along with some facts to get NOAH's point across (at around 35 seconds, the video reads "16 chickens were demonstrating for their right to a fair life." As far as we know, the chickens did not consent to being put inside a fake vending machine). The video also notes, "no chickens were harmed during the campaigning for their fellow hens."