You know that does look odd. I am going to have to scour my puma photos (both personal and books) to see what I find. I do know that with many cats the noses are pink when they are young and turn black when they get older. Not sure if this is the case with pumas or not.
When I type "mountain lion" in Google Images, all of the pictures on the screen show a pink nose except this one photo circled on the attached screenshot. However, when I click on the photo to go to the website, it is just an article about Apple's Mountain Lion operating system and does not show this photo at all. When I type "puma" in Google Images, all of the pictures show cats with pink noses (plus of course some photos of Puma brand athletic shoes). The mystery is heating up!
Great authorities have kindly informed me that this is a normal animal. The black nose is generally within normal limits of variation, but is only rarely seen. Apparently black noses are more common in Patagonian populations, but they're still rare there.