I figure the one just sat around for longer, as I've had extra blue-y cheese develop in my own fridge. Just never seen such a striking difference at the store, which I found mildly interesting.
Fun fact, if you look hard enough you can actually smell how evil the cheese is! I can tell that cheese on the left is gonna be super dry and crumbly from the texture, which I can feel through the picture, with my eyeballs.
I just like to try to get some of the light of reality to the people stuck in the shadows of their own Dunning-Kruger Effect fantasies. It's almost always completely fruitless, but it doesn't hurt anybody and, if it works, the world is that much less insufferable.