Amazon's inventory is co-mingled. So, the warehouse has the widgets sourced by Amazon itself to sell, by the widget maker themselves on their own store on Amazo

Amazon's inventory is co-mingled. So, the warehouse has the widgets sourced by Amazon itself to sell, by the widget maker themselves on their own store on Amazon, by a small chain store in one state to sell, and by random dude who might possibly be importing counterfeits to sell on his fulfilled by Amazon store. All of those widgets are in a big pile and all have the same packaging and barcodes. Whether you buy from random dude or Amazon, you're getting a random one from the pile.